The following extracts relating to the Buildings and Grounds are taken from the Annual Reports of the Astronomer Royal to the Board of Visitors. Other extracts are also available for Chronometers.
The reports were presented at the annual visitation, which normally took place in the first week of June. The first was produced in 1836. The report for the following year established a format that remained much the same until 1963, (the year before the Board was abolished).
The reports from 1837 onwards were grouped into sections dealing with different topics. The contents of the section in which the Observatory Buildings and Grounds were covered in different years was as follows:
Section 1 1837–1881 Buildings and Grounds
Section 1 1882–1931 Buildings and Grounds, Moveable property and Library
Section 2 1932–1940 Buildings and Grounds, Moveable property and Library
Section 1 1941–1947 Buildings and Grounds, Moveable property and Library
Section 1 1948–1960 Grounds and Buildings
Section 1 1961 Equipment, Buildings and Grounds
Section 2 1962–1963 Grounds and Buildings
1964 Narrative Report, Grounds and Buildings
Only the material from the above sections relating to the Buildings and Grounds has been transcribed below, together with the whole of the report for 1836.
Whilst every effort has been made to check the transcription for errors, the text is not guaranteed to be error free. Most of the reports as published can be accessed via the links below. With the exception of those for the years 1836–1839, (which come from Google Books) all the rest come from NASA's Astrophysics Data System. During the Second World War, a confidential addendum was tabled to each report containing information (relating mainly to chronometers, the Nautical Almanac Office and magnetic and meteorological data) that might have been useful to the enemy. They were never published. Copies for the years 1940–42 are held at the National Archives in ADM190/19 , ADM190/20 and ADM190/21 respectively.
* from Google books
IT may probably conduce to a more complete acquaintance of the Board of Visitors with the general state of the Royal Observatory, and ultimately to the interests and efficiency of the establishment, that a written statement should be given in from time to time by the Astronomer Royal. Under this impression I beg to call the attention of the Visitors to the following remarks:
1st. With regard to the buildings and instruments. The buildings, though not such as any person would erect for such purposes at the present time, are on the whole in a satisfactory state. Some private inconvenience arises from the circumstance, that the path to the Western Equatoreal and the Zenith Tube passes close to the bed-room windows, and considerable astronomical inconvenience is produced by the Great Room obstructing the view from the Eastern Equatoreal sometimes also low stars are lost, from the interruption by trees in the Park. There is no other inconvenience deserving notice.
The state of the meridional instruments is most satisfactory.
The Eastern Equatoreal is mounted in such a manner that there is some difficulty in ascertaining the state of its adjustments: and the divisions on its declination-circle are in several places nearly effaced. It may be a matter for the consideration of the Board, whether on some future occasion it may not be desirable to substitute an Equatoreal of better construction for the imperfect instrument now in the Western Dome.
The Zenith Tube deserves particularly to be noticed at present. I have reason to think that much of the difficulty of seeing stars well defined, &c. arose from the passage of currents of unequally-heated air near to the object-class: possibly however a part might arise from the defects of the object-glass, but upon this point I cannot yet speak with certainty. With respect to the mechanical construction, it is in my opinion seriously defective, as I propose to explain orally to the Visitors. This may, I believe, be completely corrected at an expense of less than twenty pounds.
With regard to the subject of Magnetism, I have to inform the Board, that I have received from Mr. Meyerstein of Göttingen, a complete set of apparatus for the horizontal needle (theodolite excepted,) made under the immediate inspection of Mr. Gauss. I do not entirely approve of some parts, preferring the construction mentioned by me at the last meeting of the Board (namely that in which the magnetic bar carries a collimator): but I have thought it best at all events to try this, and especially to secure a set of Meyerstein's bars, which are said to possess extraordinary magnetic force.
With regard to the locality for a magnetic erection, I beg, to lay before the visitors a rough map, regarding which more can be explained upon actual inspection. I am disposed to recommend a site beyond the precincts of the present inclosure.
The library was found upon examination to be in many respects defective. At my application the sum of one hundred pounds was placed at my disposal, for its improvement, by the Lords Commissioners of the Admiralty. Small progress has been made in this and other transactions at the Royal Observatory, for reasons to which I shall shortly allude.
With respect to the personal establishment of the Observatory, I have little to say, except that I am extremely well satisfied with the conduct of every person connected with the Observatory. It would however be wrong to omit mentioning that, though the presence of the Director is always desirable in such an institution, yet I now feel that I can at times be absent from the Royal Observatory with the most perfect confidence in its correct and able management during my absence.
With regard to the general progress of astronomical business at the Observatory, I must avow that the reductions, and (in part) the printing, are further in arrear than I could wish. This has arisen from causes such as it is impossible to provide against or to control. The observations of Halley's comet brought a mass of reductions which would be incredible to an inexperienced person. The oppression of these was increased by a cause wholly accidental. In the winter, upon the resignation of Mr. F. Simms, Mr. Glaisher, formerly assistant at Cambridge Observatory, was appointed in his place. A very extensive and beautiful series of observations on the comet had been made at Cambridge by Mr. Glaisher. Considering the interruption for two or three months of calculations and general direction at the Cambridge Observatory, considering also that a person newly appointed to the direction of that establishment would find himself wholly at a loss in the reduction of such observations, I have thought it right on my own judgment to employ Mr. Glaisher's time as calculator principally on the reduction of these Cambridge Observations. I trust that I shall have the approbation of the Board for this determination.
In the month of April, application was made by the Plumian Professor and several Members of the University of Cambridge, to the Lords Commissioners of the Admiralty, to allow of my absence, for the purpose of giving a course of lectures in that University: and permission was accordingly granted by their Lordships. It was impossible that this could be (lone without some retardation of the extraordinary business; for instance, the institution of magnetic observations, experiments on the zenith tube, completion of the library, and the like: but I have much pleasure in stating my belief, that the ordinary business was carried on, under my epistolary superintendance, with the usual regularity and completeness.
The principal business for the last half year has been – with the Transit, the R.A. of principal stars and Sun, Moon, and planets: with the Circles, the polar distances of stars proper for latitude and refraction, and the polar distances of Sun, Moon, and planets. The moon and planets have been followed through the whole night.
The Solar Eclipse of May 15 was most completely observed. Preliminary calculations are now going on for the complete reduction of 206 micrometrical observations made during the eclipse, in the same manner as that detailed by me in a paper on the eclipse of 1833.
As a matter of occasional astronomy, I beg to call the attention of the Visitors to the circumstance, that Ramsden's sector is now fitted up in the Front Court, at the request of Colonel Colby, and under the immediate care of Lieutenant Denison, of the Royal Engineers, for the purpose of verifying its whole arc by comparison with the Greenwich Circles. I have several years wished to accomplish this desirable object; and I hope that it will now be effected in the most satisfactory way.
The printing of the Observations of 1835 is not terminated, as the Comet observations are not yet wholly ready for press. The printing of those for 1836 is not commenced: and before commencing it, I beg to call the attention of the Board to the expediency of the following points :
l. The printing in quarto.
2. The arrangement on a plan to be pointed out by me, nearly similar to that of the Cambridge Observations.
3. The publishing annually instead of quarterly.
The only remaining subject, in the general business of the Observatory, is the care of chronometers. I have on a former occasion expressed to the visitors my belief, that the oppression of business arising from the care of chronometers has been most injurious to the astronomical efficiency and general reputation of the Royal Observatory: and I take this opportunity of repeating that belief. I also beg to remark, that this oppression has not been produced by that part of the business which relates to the rating or reporting upon or experimenting upon chronometers, but by that which relates to the money accounts, the accounts of chronometers in store, &c., and the delivery of chronometers to ships. At my representation, alterations have been made in several of the arrangements, the effect of which has been to diminish in some degree the various interruptions to the astronomical business of the place. If at any subsequent time it should be necessary for me to request an expression of opinion from this Board, I trust that I may represent their sentiments correctly by saying, that the persons of this establishment are astronomical observers and calculators, not clerks; that the Observatory is an astronomical institution, not a storehouse; and that any regulation which makes the account-keeping and store-keeping department predominant over the astronomical is an unjustifiable and injurious diversion of its powers.
I. Grounds and Buildings. – The report of the Board of Visitors in the last year having suggested to the Lords Commissioners of the Admiralty the propriety of inclosing, for Magnetic Observations, a large extent of ground, a plan was furnished by me to their Lordships of the portion of the Park which it appeared desirable to annex to the Royal Observatory: and I had the honour at the same time of laying before the First Lord of the Admiralty a statement of the extreme smallness of our previous inclosure, as compared with that of any other modern observatory with which I am acquainted. An application was accordingly made to the Commissioners of Woods and Works: and, the matter being warmly taken up by the Chancellor of the Exchequer (to whom on this, as on many other occasions, the science of the country is deeply indebted), the consent of the King, as well as that of Her Royal Highness the Ranger of the Park, and of other parties, was obtained without difficulty. By Mr. Rhodes, as representative of the Board of Woods and Works, I was formally put in possession of the ground: and within a short time, the external inclosure has been completed. Some small internal arrangements are yet necessary before the ground in question will be available for a public erection: but there is every prospect that magnetic observations will be commenced in the course of the coming summer.
I. Grounds and Buildings. – In the last report I stated to the Board, that the ground necessary for the erection of a building for magnetic observations had been externally inclosed, and that I expected shortly to be able to commence magnetic observations. In this I have been partly disappointed. Some little time was consumed in arranging the approach to the ground, dividing it from the private garden, &c.: and a greater delay occurred in the erection of the building itself. This delay arose from causes in which I had no part, and over which the Government had no control. A change took place in the office of Admiralty Surveyor of Buildings: the contractor who had engaged to erect the building of concrete, was unable to execute his engagement: and when at length it was found necessary to resort to wood for the material of building, the extreme severity of the weather suspended all operations for some time. From these causes it happened that the key of the building was not placed in my hands till the beginning of May. Since that time workmen have been employed in arranging the supports for a large horizontal needle: and I am now able to exhibit to the Board the whole plan of the proposed magnetic observations. The observations themselves have not yet commenced: some adjustments of the theodolite being not yet made, and some tables for facilitating the reference to the astronomical meridian being not yet completed: but in all important respects the instrument is ready for use.
With regard to the buildings in general I have no particular remark to make. But I wish to suggest for the consideration of the Board, -whether it might not be desirable to fit up the room known by the name of the Second Quadrant Room, as a Muniment Room, for the preservation of the manuscripts and other valuable articles, which are or may be lodged in the Observatory. I am induced to offer this suggestion, first, because the old part of the house (including the Octagon Room) appears to me peculiarly exposed to destruction by fire; secondly, because it is not unlikely that, in the event of new standards of length and weight, adapted to the most accurate purposes, being constructed by the Government to replace those lost at the conflagration of the Houses of Parliament, it may be thought desirable to lodge them at the Royal Observatory. The expense of altering the room for the purpose mentioned would be very small.
I. Grounds and Buildings. – At the last meeting of the Board, I suggested the advantage of inclosing and fitting up the room, known by the name of the Second Quadrant Room (being the western portion of the room known in Bradley's and Maskelyne's time as the Quadrant Room), in such a manner as to render it a safe room for the deposit of manuscripts, and other valuable articles. The suggestion having been approved by this Board, and having been laid before the Lords Commissioners of the Admiralty, was by them immediately referred to their Civil Architect for plans and estimates. The Lords of the Admiralty having in the last summer personally inspected the Observatory, and having been struck with the inconvenience arising from the want of an inclosed communication between the Observatory and the Dwelling-house of the Astronomer Royal, were pleased to suggest that a covered passage should be constructed at the same time as the inclosing of the Muniment Room. The financial arrangements of the Government prevented any steps from being taken until the Estimates for the present year should have been sanctioned by Parliament. Since that time, the plans and specifications for the various parts of the work have been placed in the hands of the builders; and I have every reason to think that the work will be proceeded with in a very short time.
One side of the proposed room will be formed by the pier carrying (on that, side) Graham's Quadrant and the Fixed Telescope erected for the observations of α Cygni. I have thought it desirable to remove the Fixed Telescope, but to retain the venerable Quadrant in its place, and even to put it in such order that, if any future astronomical antiquary should desire, observations may be made with it. The room is to be covered with arches of brick-work: but by leaving vacant a part at the end of one of these arches, and by covering it with a flat stone, which can be removed with little trouble, the command of the northern opening will be given to the Quadrant Telescope. The iron-work of the Quadrant had formerly been painted: but it had, from neglect, suffered materially from rust. I have caused it to be cleaned and painted, under the personal inspection of Mr. Simms: and the limb and verniers, with other small parts, were carefully cleaned at the same time. I may remark that the object-glass appears to be achromatic: I know not whether there appears in the publications of the Observatory any memorandum of the time when this object-glass was inserted.
The Board are aware that a meridian mark (a pillar of granite) was erected under the direction of Mr. Pond, in the year 1824, at Chingford in Essex, upon one of the hills projecting from Epping Forest, on a piece of ground leased to the Board of Admiralty for ninety-nine years from that time. Although this mark is not used by me in the same manner as by Mr. Pond, in the occasional adjustments of the Transit, yet I am fully aware of the advantage of keeping it in repair, and sometimes observing it, for the purpose (if there were no other) of noting the direction of a line of several miles in length, which in 1824 was as nearly in the meridian as it could be placed by the best instruments in the world. Some small steps have therefore been taken by me for the preservation of the fence, &c.; and I propose to regard it as an object whose careful conservation is well worthy of attention.
Nothing else has occurred in regard to the Buildings and Grounds, which seems to call for the least remark.
I. Grounds and Buildings. – In the Report read to the Board at the last Visitation, I stated that steps were in progress for the construction of a fire-proof room in one side of the old Quadrant-Room (as recommended by the Board at the meeting preceding the last), and for the formation of a covered passage from the dwelling-house of the Astronomer Royal to the Observatory. These works were completed in the last summer. A set of iron shelves has been mounted in the fire-proof room, for the support of manuscript books, &c.: it was found necessary in the last winter to conduct a stove-pipe through the room, as the only way of keeping the books, &c. dry in the alternations of temperature at that season; but it is conceived that this is (lone without danger to the contents: of the room. The passage is found to be not only of great convenience but also of very great utility. Indeed, it is impossible to estimate how much more frequent will be the visits of the head of any establishment to every part of the offices subject to him, when, instead of encountering the inclemencies of weather in order to reach the nearest of them, he is able to pass through very nearly the whole without involuntary exposure.
No other addition has been made to the buildings, except the covering of a small square at the entrance of the North Terrace, so as to form a sheltered space, in which boxes of instruments, &c. may occasionally be placed. The want of such a shed had often been felt.
Within the last year, the attention of the Civil Architect of the Board of Admiralty has been called to the state of the North Terrace wall. The wall, probably from an injudicious mode of building and from the effects of water and frost, has bulged out considerably; and the foundations, not only of the wall but also of the whole of the northern and western faces of the house and of the court-wall, have been completely exposed. This appears to have arisen from the gradual crumbling down of the steep hill, assisted as it is by the continual treading of the enormous number of persons, who, on every fine day, are walking beneath the terrace wall. The Civil Architect proposes, as I believe, to recommend that the wall be rebuilt, and that a portion of the walk below be completely paved, as the only way of preserving the foundation of this venerable building.
At the last meeting of the Board I was desired to procure information relative to the place of Flamsteed's well. I have communicated on this subject (indirectly) with Mr. Taylor, formerly First Assistant at the Royal Observatory; and with Mrs. Storey, daughter of Dr. Maskelyne. From the former I have received only an expression of full confidence that no such well was ever discovered; by the latter I am assured that such a well was discovered, but was closed so quickly that even Dr. Maskelyne himself did not see it. With regard to the locality, I apprehend that no more certain information can be obtained than that deduced from the accurate plan left by Flamsteed (and published by Mr. Baily, in his Account, &c. of Flamsteed), from which it appears to be exactly at the meeting of two walls, bounding what are now called the Drying Ground, and the Middle Garden.
I have this day received a communication which seems to require the distinct attention of the Board. The proposal of conducting a railway to Chatham, through the bottom of the Park, having been given up, another plan has been formed for carrying a railway across Blackheath, approaching very near to the south-western corner of the Park; and the plan has this day been sent to me by the engineer (Mr. Vignoles), with a request that I would lay it before the Board for their consideration, as the representatives of the astronomical interests of the Observatory.
I. Grounds and Buildings. – No alteration whatever has been made in the grounds of the Observatory since the last Report. No progress, so far as I am aware, has been made in the arrangements for the Chatham Railway, noticed in the last Report. I have, however, understood that a line a little more distant than that there alluded to is at present meditated. No other external circumstance occurs to me as worthy of notice.
The front wall of the North Terrace has been rebuilt: and a flagged pavement has been laid round the foundation of that part of the Court Wall which appeared to be in the greatest danger. The old Camera Obscura has been removed from the north-western turret of the Great Room, to make way for the Anemometer, which I shall mention further below. Some additional shelves have been fitted in the Library, and some of the old ones have been altered, for the reception of additional books. A small wooden house, the property of Capt. Fitzroy, R.N., which was carried by him, in the Beagle, in his circumnavigation of the globe, has been planted in the southern part of the Magnetic Ground for observations of the dipping-needle, and any other observations which would be prejudiced by the action of the large magnets in the Magnetic Observatory.
I. Grounds and Buildings. – Everything remains in the same condition as at the last Visitation of the Observatory, with only the following alterations: - The vastly-increased business of the Observatory (including the Planetary and Lunar Reductions, and the: Magnetic and Meteorological Establishment) making it very desirable that a convenient place for office-work, in easy communication with the assistants generally, and, at the same time, in the immediate neighbourhood of the books and papers most frequently referred to, should be provided for myself: I represented to the Lords Commissioners of the Admiralty the advantage of enlarging the Computing-room, according to a plan which I presented. Their Lordships, although no sum had been provided upon the annual estimates, were pleased to accede to my urgent representation, and the work was immediately dispatched. This transaction occurred in the course of last summer. The Great advantage gained will be obvious to the Visitors, who have seen the Computing-room in its present state, and who remember it in its former confined dimensions, when I was compelled to place in my own dwelling apartments all the books and papers which were not actually in use, and were not so old as to be stored away in the Safe-room; and when much time was lost by reference from one room to another.
An alteration has been made in the wall-shutters of the Transit-room and Circle-room. It will be remembered by the Visitors, that Dr. Maskelyne, in one of the volumes of his Observations, mentions with very great interest the alteration which had then been made in the shutters of the Observing -rooms, to allow a wider opening to be used in observation. When the method of observing by reflexion was introduced by my respected predecessor, it became necessary to provide means of contracting the apertures, in order to prevent the disturbance of the surface of the mercury by strong currents of air; small doors were therefore inserted in the central part of the shutters: it became therefore easy to display the narrow apertures, and troublesome to open the large shutters; and the consequence was, that the large shutters were never opened. I have now made such an alteration, that in the Transit-room the full width only can be used, and in the Circle-room it is easier to use the wide opening than the narrow one. With reasonable care, I trust to obtain the advantages reckoned on by Dr. Maskelyne, retaining the power of protecting the mercury from the wind, which is necessary for reflexion-observations.
The trussed frame, which was erected some years back, for supporting the Ordnance Theodolite above the Octagon-room, resting only on the walls of the Observatory, was found, on examination, to be so much decayed in several important parts, that if occasion for its use should again occur, it would be necessary to take it to pieces for restoration: I have therefore thought it prudent to remove it entirely.
I. Grounds and Buildings. – Under this head I have nothing of the smallest importance to communicate to the Visitors. No addition has been made to our erections, no alteration in the arrangement of rooms has been found necessary, and no expensive repair has been required. In the next year it will be proper to renew the painting, &c., of some parts of the interior of the dwelling-house, and of the Octagon-room: but I do not anticipate that any other repair, except of the most ordinary kind, will be needed.
I. Grounds and Buildings. – At the time of the last Visitation, there was erected on the Magnetic Ground a small framed Observatory, which had been constructed by Captain Fitzroy for use during his voyage round the world in the Beagle, and which, on his return to England, he had lent to the Royal Observatory. This small building was used here for the observation of the Magnetic Dip. On Captain Fitzroy's departure to assume the government of New Zealand, he was desirous of taking with him the same building, for the prosecution of the magnetic observations which he intended to continue there. It was necessary therefore immediately to provide a new building: and a small wooden erection, which the Visitors may have seen in the extreme southern part of the Magnetic Ground, was constructed for the observation of Dips and for other observations which could not be carried on in the neighbourhood of the great magnets. Its roof is double, with a free passage for air between the two coverings. It is found to be generally well adapted for its purpose.
The Visitors will remember the tenor and urgency of their representations to the Board of Admiralty, agreed on at their meeting of November last, regarding the proposal of erecting a proper Altitude and Azimuth Instrument for extension of the series of observations of the Moon, in conformity with the plan which I had the honour then to submit to them. The Board of Admiralty at once sanctioned the principle of this proposal; and, on their application, the Lords Commissioners of the Treasury without hesitation sanctioned the estimated expense. In the paper which I had laid before the Visitors, I pointed out two sites, either of which appeared well adapted for such an instrument. One was a little in the rear of the Chronometer Room and South Dome: the other was the Advanced Building (formerly the place of Flamsteed's Equatoreal Sector). I at length determined on adopting the latter. The walls have accordingly been erected on the walls of the Advanced Buildings, and the structure, though not yet complete, is in such a state of forwardness that the Visitors can examine the arrangement of every part. The preparation for mounting the Instrument is made, but the flat dome for covering it, though in progress, is not yet completed. The Deputy Ranger of the Park consented, on my application, to cut off the top of the only tree which interfered materially with our view near the horizon; and the command of the sky is now almost complete. I may mention here that, in stripping the old walls of the Advanced Building, traces were found of windows or doors in each of its three sides (the fourth side being that which joins to the observing buildings). These windows are not represented in Flamsteed's plans: it seems very unlikely that they were opened since his time; and on the whole I should suppose that they were walls of some outbuilding of the old Greenwich Castle. It is to be remarked, however, that the western wall, which contains one of these unexplained windows, ranges due north and south (the others being inclined to the cardinal points); but as Flamsteed's arc was attached to its outside surface, and as the window does not pass through the whole thickness, which is 28 inches, it seems certainly anterior to Flamsteed's time. It can hardly be conjectured that it was made for anything like a meridian line. In the center of the building, under the paved floor, was a pier of later date, covered with a massive block of stone.
The Visitors may have remarked, also, a small building containing a pier of brick and, tone, adapted for observations with a portable transit, which is now erected on the Magnetic Ground. This has been erected for the observations which Mr. Struve is about to make, for determining, by transmission of chronometers, the difference of longitude between Greenwich and Altona, as part of the difference of longitude between Greenwich and Pulkowa. Mr. Struve's plan, of interchanging the observers at the two ends for the elimination of personal equation, makes it almost necessary that he should have the complete command of a transit instrument; but the combination of the observations made at this instrument with those made by our own observers with our own transit will be extremely easy. Mr. Otto Struve has already arrived to make the first preparations, and to conduct the first half of the observations; and I expect to be honoured with a visit from Mr. Struve himself, as soon as the regular interchange of chronometers shall have commenced.
I. Grounds and Buildings. – At the last Visitation, the walls, floors, and pier for the tower erected on the site of the Advanced Building were completed, but the flat topped dome was not constructed. This was completed shortly after that time. The dome turns upon common balls, moving freely between concave channels: a construction which allows of easier motion and is less likely to interruption by accident than any other. The sides and top of the dome are double, the inner lining being of wood and the cuter casing of zinc. The space between them is about 6 inches wide, and throughout this space there are no fillets or continuous bars of wood, but merely isolated blocks, to which the zinc casing is attached. The zinc top is not connected with the zinc sides, and the zinc sides are not connected wish the lower curb of the dome, a space of about 4 inches being left in each of these places: so that there is ample facility for the circulation of air throughout the space between the inner lining and the outside casing. This construction appears to answer the purpose for which it was intended exceedingly well. The temperature seems to be uniform in all parts of the room, and appears to correspond nearly with that of the free air, even when the sun is scorching hot. The doubleness of walls and roof makes it necessary to use, for the shutters, instead of hinge motion, which is usually best in practice, a motion of sliding laterally. - This is made to work «ell, by attaching a rack to each end of the shutter and causing these racks to work in pinions fixed at opposite ends of the same spindle. This machinery is concealed in the space between the inner lining and the outer casing. The same principle is adopted for the wall shutter and for the roof shutter. The whole construction appears to answer well. The stationary parts of the mounting for the instrument to be placed in this dome have been long fixed, but the instrument itself is not yet mounted.
The small Observatory, upon the Magnetic Ground, intended for Mr. Struve's use, which was already erected at the last Visitation, and which was employed for its original purpose during the last summer, has since that time been unoccupied. I propose, however, to retain the building in its present state until some strong reason for its removal shall present itself, as it is sufficiently probable that occasions may again arise requiring the use of a portable transit instrument.
No important change has been made in the grounds and buildings, and no repairs requiring mention, except that the Octagon Room and some other parts have been painted, an operation which implies a great number of trifling repairs.
In the last winter I received authority from the Board of Admiralty to prepare a proper map of the Observatory and grounds, with a notice that their Lordships would provide for its being engraved. The measures of all kinds have been made, and most of them have been laid down, but the ill health of the person employed as draughtsman has delayed the completion.
I. Grounds and Buildings. – In regard to the Buildings of the Royal observatory, very little alteration has been made in the last year. The external walls, coverings, and fences, remain in every respect in their former state. A few internal alterations have been made. A shed, which was built a few years since in the place that then appeared to be the cheapest for its purpose, has now been removed to a place which is much more convenient. The rails of my private garden have been shifted so as to inclose a narrow strip of broken ground which was never used for observations of any kind. The want of additional shelves becoming pressing, a considerable extent of slate shelves has been erected in the Safe Room, and of wooden shelves in the rooms under the New South Dome and in the Magnetic Building. At the present time a porch for the Magnetic Building is in the course of construction.
The Map of the Grounds and Buildings, to which allusion has formerly been made, having been long delayed by the illness and ultimate death of Mr. R. Harris, has been taken up by Mr. James Breen (one of the Computers usually employed on the Lunar Reductions), and is now nearly ready for engraving.
In regard to matters external to the Observatory Inclosure, although no step has been taken affecting the material walls and grounds surrounding us, yet discussions of a very important character have been for some time going forward which it is proper for me to lay before the Visitors. One of the railways proposed for the accommodation of the northern parts of Kent, promoted by the South-Eastern Railway Company, is designed to pass through the lower part of Greenwich Park in a tunnel at a distance between 800 feet and 900 feet from the observing rooms of the Royal Observatory. Experiments were made by me in the spring of the present year to determine the probable effect of such a railway, more especially in regard to the sedative effect of the small covering of earth above the tunnel. Experiments on the general effect of a railway had been made by me about ten years since. The results of these experiments, though not very distinct, are yet, in my opinion, sufficiently distinct to enable us to decide on the course proper to be pursued in relation to the proposed railway through the Park. The experiments of every kind have been communicated to the Admiralty, and by that Department arrangements were made with the South-Eastern Railway Company to the following effect (as is understood from the public newspapers), that the Lords Commissioners of the Admiralty consented to the passage of the Railway through the Park, on the introduction of a clause in the Railway Bill authorizing their Lordships from time to time to establish regulations for the speed and weight of the trains passing through the Park, or, if necessary, to stop the traffic entirely. With this understanding, the Bill received the sanction of the Railway Committee to whom it had been referred. Its progress through the House of Commons has, however, been for the present suspended; and I believe that the House of Commons have, by Order of the House, required the production of all papers illustrating the probable effect of the Railway upon the Observatory.
I. Grounds and Buildings. – In the last Report to the Visitors, I adverted to a porch for the Magnetic Observatory, then in progress of construction. This porch was finished a short time after the last Visitation, and has been found to be a convenient addition to the Magnetic Building.
Besides this, no addition has been made to the buildings, and no alteration of the most trifling importance, except in the erection of a small wood-built and copper-fastened room attached to the north side of the Dip-house, now nearly completed. This room is intended for the reception of the Magnetic Theodolite; it being intended that a magnet, whose absolute declination is to be observed, shall be mounted (when required for use) in the adjoining Dip-house. I have undertaken the arrangement of the declination-apparatus in this form principally in deference to the strongly-expressed opinion of several of the magnetic observers who were present at the Magnetic Congress held at Cambridge: for my experience of the steadiness of neutral point of the torsion-circle in our magnet-suspension, warrants me in the belief that no important error has resulted from the use of the same magnet for absolute determinations and for occasional changes of declination.
The erection denominated the New South Dome, built on the walls of the ancient Advanced Building, has now, by the mounting of the Altitude and Azimuth Instrument, come into practical use; and it has been found to be generally convenient and well adapted to its purpose. The dome-shutters move very well; and the dome itself revolves so easily that it has been found necessary to attach an apparatus for stopping it in any required position.
The Map of the Grounds and Buildings is now completed, exhibiting the state of the Observatory in December, 1846. A small map (reduced from the larger one) has been lithographed, and will be published in the Observations for 1845.
At the last Visitation of the Observatory, the attention of the Board of Visitors was called, by the Lords Commissioners of the Admiralty and by myself, to the plans then in agitation for the construction of a Railway to pass in a tunnel through the lower part of Greenwich Park. The formal history of the proceedings connected with this proposal, subsequent to the meeting of the Visitors, is, I believe, as follows. The Board of Admiralty, on consideration of the opinions laid before them, retracted the permission given to the Railway Company to prosecute their works through the Park; and the Legislature sanctioned a line, passing round the south side of Blackheath, and gaining the valley of the Thames by a tunnel under the neck of land which connects Blackheath with the heights that extend to Shooter's Hill. The first shaft for excavating this tunnel has very lately been sunk, on the Charlton road.
I. Grounds and Buildings. – The room formerly occupied by the 25-feet Zenith Tube, has been vacated by the removal of that instrument (in conformity with the Resolution of the Board, passed at their meeting of January 15 of the present year). The N. W. Dome, adjoining the Zenith Tube Room, had already been left empty by the dispatch of the N. W. Equatoreal to the Cape of Good Hope. These two rooms were likely to be never again occupied by astronomical instruments: for, in addition to the general unfitness of position and access caused by their proximity to my dwelling-house, each of them was characteristically unfit for the instrument which it contained. The N. W. Dome, appropriated to an equatoreal, which ought to command the sky in nearly all directions, is overshadowed in the S. E. quarter to the height of 50° by the Great Room. The Zenith Tube Room is so situated that the difference of temperatures above and below is usually great; and its difference of latitude from the Circle Room is uncertain to an amount incompatible with the connexion of the series of observations made in the two places. I am, therefore, at the present time engaged in preparations for connecting these rooms with my dwelling house. As regards the N.W. Dome this is only a resumption, for that room was originally a part of the dwelling house.
The lower story of the N. E. Dome has hitherto been a passage-room. In the great want of space for every purpose at the Observatory, I have found it desirable to make this room useful as an inclosed room, and I am accordingly preparing a new entrance into the Dome.
An old kitchen in the East Buildings has been nearly useless. I have, by a small alteration, converted it into a useful room.
I now request the attention of the Board to the change which I propose to make in the Circle Room, in preparation for the New Transit-Circle, of which I shall speak shortly.
It appears, that a length of about 35 feet is necessary for the instrument and its collimators, in the form in which I propose to mount them. I propose to gain this space by extending the Circle Room southward, into my private garden, so as to range in its south front with the south front of the East Buildings. The ridge of its roof may be either E. and W. or N. and S.: the latter probably would be more convenient. If it were adopted, the arrangement of roof-opening and shutters would be nearly the same as in the small building called Struve's Observatory. The two stone piers which now carry Troughton's and Jones's Circles must be moved to new positions. For the roof-shutters, I propose to use hinged flaps, balanced and moved nearly in the same manner as those of the Berlin Observatory. During the change of the Building, it will not be possible to use either Mural Circle in its usual place. Preparations accordingly are nearly completed for mounting Troughton's Circle on the wall of the East Buildings. Some parts of the Circle are already removed, and during this time Jones's Cape Circle is employed. Thus the Circle-observations will be continued without the smallest interruption. The Transit-observations will be in no way affected until the new instrument shall be completely mounted: after that time the Transit Instrument may be removed, and the Transit Room will be free for any other purpose. I propose to take it as Private Room for the Astronomer Royal: a purpose for which its neighbourhood to the Computing Room and the Observing Rooms adapts it well. The Computing Room would thus be relieved from its present pressure. A passage taken from the south side of the Transit Room would form a convenient communication between the Computing Room and the Observing Rooms.
I. Grounds and Buildings. – In the Report of last year I stated to the Visitors that I was then engaged in preparations for the annexation to my dwelling house of the Northwest Dome and Zenith Tube Room. This work was completed in the summer of last year. This arrangement, while it adds in various ways to the comfort of the Astronomer Royal, is also a matter of positive advantage to the Observatory. It is a real Gain that an absolute impediment should be opposed to the mounting of instruments in localities so extremely unfit for them as were those of the North-west Dome and Zenith Tube Room.
The erection of the Transit Circle Room is now completed. This work has occupied nearly the whole time since the last Visitation of the Observatory. At that time Jones's Cape Circle was in use, preparations having been already commenced for removing Troughton's Circle to a shed or Temporary Observatory attached to the East end of the East Buildings, its long axis passing through the wall of the building and lodging on a pier built within a room. The Circle was used in this place for the first time on July 22; Jones's Circle was then dismounted, and stowed away on the Magnetic Ground, and the old Circle Room was pulled down. It will be remembered by the Visitors, that I proposed to use the Piers of the Two Circles for the new Transit Circle, and that one of the Piers was to be bored for eleven Microscopes passing through it in a conical arrangement, and for eleven Illuminating Holes whose axes are distributed on the surface of another cone. After an unsuccessful attempt to bore the Pier of Troughton's Circle (the material of which was found to be a stratified grit-stone, called by the workmen " Dundee Granite"), Jones's Pier (of Portland Stone) was bored. The axis of each hole, small and great, was bored completely through before the Pier was disturbed. The Piers were then taken down, and their stones spread over the Front Court, and the enlargement of the holes (a very troublesome operation), and the cutting of the stones where required, were completed there. It may be worth mentioning, as a point in the history of the instruments, that on taking down Jones's Pier it was found that the upper part of the western wall of the East Buildings rested upon the Pier. The Piers were then rebuilt in their new position, and the walls of the room were built up. The roof and shutters were then arranged in general conformity with the plan which I had indicated at first, namely, with the ridge of the roof N. and S., and with hinged flap shutters, balanced by counterpoise-weights, and moved by machinery nearly similar to that at the Berlin Observatory. The 'all-shutters are simply doors, managed by no very complex machinery inside. The whole of this is now completed, and will probably be worthy of the attention of the Visitors. The Piers for the Collimators are built; the Collimators, though in the room, are not yet mounted, as I propose to mount a 5-feet transit-instrument in a temporary way, so as to enable me to determine the meridional direction with great accuracy, and by means of this to plant the Collimators very exactly in their proper positions. In the external architectural arrangements, I have endeavoured to give a face harmonizing with other parts of our buildings.
I have hitherto made no preparation in the buildings for the intended Reflex Zenith Telescope. I propose to plant it in the small low room which is attached laterally to the Transit Circle Room, and which has contained for some years past only a desk and a chest of drawers. A pyramidal flue of the old stove will make a firm foundation for the quicksilver. But as it is necessary that both the trough of quicksilver below and the eye-piece above should be easily accessible, I am unable to arrange the building until I know the length of the telescope. If the old 25-feet object-glass be mounted, it will be necessary to raise the building to the windows of the first-floor. Perhaps, however, it will be more convenient to use the object-glass of the present Transit-Instrument; or, perhaps, it may be possible to obtain an object-glass of larger aperture. In either of these cases it is most likely that the height of the existing room would suffice.
At the present time, operations have been commenced for an alteration in the approaches to the Octagon Room. For many years this room has been in a state of insulation; for, by the necessary closing of the old entrance into my dwelling -rooms by the side of the Ball Clock (these rooms being entered, ever since the construction of the southern apartments for Dr. Maskelyne, from' the long passage of the house), there is no access to the Octagon Room except from the open air. At the same time the room has become a passage room; formerly to the Camera Obscura in its western turret, then to the upper apparatus of the Time Ball; but, finally, for the daily access to the two self-registering Anemometers mounted on the leads. To remedy these inconveniences I am now commencing the construction of two, staircases ; one rising from the long passage of my dwelling-house, and entering at the south-eastern window of the Octagon Room; the other an external broad-staved ladder rising from the new entrance of the North-east Dome to the leads of the Octagon Room. When these are completed, the whole series of buildings will be in a state of communication vastly superior to any in which they have been before the present time.
The North Kent Railway, as I stated in a former Report, is now carried in the valley which nearly surrounds Blackheath on the south side; and its works are at this time almost completed. It will be remembered by the Visitors, that when the question of carrying this Railway through Greenwich Park was discussed, the Visitors supported with their judgment the opinion which (guided by experiments) I had expressed, namely, that the Railway in that place might cause some small inconvenience to the Observatory, but that it would produce no serious injury to it. In confirmation of this judgment I beg leave to state that I have lately visited the Observatory of Edinburgh, built on the Calton Hill; the North British Railway is there carried actually through the same hill, at a linear distance from the Edinburgh Observatory, apparently less than that of the proposed line in Greenwich Park from the Royal Observatory; the rock of the hill is hard, and apparently very likely to transmit vibrations; yet, as I am assured by Professor C. P. Smyth, no inconvenience of the smallest kind is felt in the Observatory.
For several reasons, it is convenient to terminate the Report with the end of a lunation; and it is therefore to be understood generally that the account now presented to the Visitors applies to the state of the Observatory on May 11.
I. Grounds and Buildings. – The subject of my principal remarks in the Report of last year was the erection of the Transit-Circle Room. Since the last Visitation, no change has been made in that apartment. And I am enabled by the experience of one year to speak most favorably of the principles adopted in its construction. Not a drop of water has entered at the shutters, either of the roof or of the walls. The shutters are managed easily, and every single shutter is independent of every other. When the shutters are opened, the surface which is next to the path of the light falling on the object-Mass of the telescope is cool (not having been exposed to the rays of the sun), and will therefore not disturb the vision by the mixture of hot and cool air in the shutter-opening. And I would recommend that the same construction should be adopted in every new meridional observatory : that is, that the ridge of the roof should run north and south ; that the roof-shutters should be upon the ridge of the roof, and the wall shutters in the middle of the end-walls ; that all the shutters should turn on hinges opening outwards, the hinges being on the east side (unless there is any peculiar reason for objecting to this) ; and that each place of meeting of the separate roof-shutters should be covered by a small supplementary shutter, to be lifted by the elevation of either of the adjacent principal shutters.
The room for the intended Reflex Zenith Telescope is now prepared in the place which I indicated in last year's Report, namely, in the small apartment at the north-east corner of the Transit-Circle Room. The walls have been raised, and a flap shutter has been mounted on the roof; the floor which is to carry the instrument is fixed about five feet above the Transit-Circle Room floor, and the pier which is to carry the mercury-trough is built on the pyramidal stove-flue below it. The height of the pier- as at present adopted has been computed on the supposition that the object-glass of the existing Transit instrument will be used for the Reflex Zenith Telescope; if any other object-glass should be used, it will only be necessary to raise or lower the pier by half the difference of the focal lengths.
The changes in the approaches to the Octagon Room and the leads above it, to which I alluded in my last Report, were completed shortly after the Visitation. The Octagon Room is now accessible by an easy staircase from the principal passage of my dwelling-house; and the leads are reached by an external ladder-staircase, rising from the new south door of the North-east Dome. Great convenience has already been found in these changes.
Workmen are at this time employed in laying gas-pipes for the illumination of every part of the Observatory and of the dwelling-house.
THE Report which I have the honour now to present to the Board of Visitors is intended to convey an account of the state of the Royal Observatory on 1851, May 30; and of the proceedings in the Observatory from 1850, May 11, to that time.
I. Grounds and Buildings.-In previous communications to the Visitors I have pointed out the want of an Official Room for the Astronomer Royal, and the facility with which this could be supplied as soon as the Transit Instrument should be dismounted. This has now been done. At the beginning of the present year, as soon as the competency of the Transit-Circle for work was established, the Troughton's Transit was taken down, the piers were removed, the room was dismantled of all astronomical appurtenances, a doorway was pierced through the wall of the Computing Room (close to the south wall of the Transit Room, and opposite to an existing doorway leading into the Transit-Circle Room), and an east-and-west wall was built in the Transit Room, so near to its south wall as to leave only a passage equal in breadth to the doorways. This passage makes a communication between the Computing Room and the Transit-Circle Room; the remainder of the Transit Room forms the Astronomer Royal's Official Room. The doorways formerly existing give immediate access from it to the Computing Room on one side, and to the Transit-Circle Room on the other. The old observing -shutters were taken out and replaced by rough glass, and the room is now extremely well lighted.
The ground-floor room of the North Dome (formerly called the East Dome, and lately the North-east Dome) was for more than half a century useless, because it was used as a passage-room. A most insignificant alteration of doors and windows, effected about two years ago, made it available as a separate room, with a convenient access. For some time past it has been destined to contain the Galvanic Registering Apparatus to be employed on the American principle, for recording the Transits observed with the Transit-Circle and the Altazimuth; and in the last year the basement has been prepared (by inserting windows, paving the floor, and placing a ladder) for the Galvanic Batteries and other rough apparatus required in the American register. The rooms, however, are not yet occupied.
It will be necessary soon to increase our Library accommodation; and I have begun to make preparations for this extension, by removing the Chronometers from the room which they have many years occupied (adjoining the Library) to a room above the Computing Room, formerly used as an Assistant's sleeping-room, but for many years past nearly useless. The Old Chronometer Room is at present used for a temporary purpose, but I intend before long to fit it up with Library Shelves, The New Chronometer Room is somewhat larger than the old one, and it is furnished with an apparatus for warming a limited number of chronometers by the heat of gas-flames, copied from that established in the Liverpool Observatory. Adjoining to the Chronometer Room is a small room now used as Office for the transaction of Chronometer Business.
The Manuscript Room is becoming exceedingly crowded. Workmen are at the present time employed in erecting shelves and cabinets on the east wall of the Astronomer Royal's Room, which it is intended to appropriate to some of the Manuscripts, especially those of a more confidential class.
Gas illumination has now been introduced in all the buildings and on all the instruments, as far as I think it desirable to employ it.
On matters external to the observing buildings, I have only to record that the demand for open shelter has become more and more pressing, and I have therefore commenced the erection of a large Shed on the east side of the Magnetic Ground.
THE Report now laid before the Board of Visitors embraces the history of the Observatory during the twelve lunations from 1851, May 30, (the epoch of the last Report), to 1852, May 18, and applies to the state of the Observatory on the day last mentioned.
I. Grounds and Buildings. – In the Grounds and Buildings of the Observatory, using these terms strictly, there has been very little change during the past year, and scarcely anything except what was pointed out in the last Report to the Visitors, as either then commenced or in contemplation. The Old Chronometer Room has been fitted up with shelves for increase of Library accommodation, and one extensive class of books (Transactions and Serial Works) has been removed to it. A room near it has been appropriated to Stationery Stores. By the effect of these and other alterations in the occupation of the Observatory buildings, there are no rooms of any kind now left available as sleeping chambers for the Assistants. The experience of many years, however, has shewn that such apartments are not wanted. The Shelves for Manuscripts in the Astronomer Royal's Official Room are completed, and a portion of the Manuscripts is transferred to them. The large Shed on the east side of the Magnetic Ground is completed.
On the outside of the Observatory fence, however, an important work has been executed. In the last and in preceding Reports, I had alluded to the probability of our requiring, in no long time, a galvanic connection with London and with the Continent of Europe. In the last autumn, the Submarine Telegraph between the South Foreland and Sangatte, in France, was successfully completed, and in a very short time afterwards I received from some of the active members of the Institute of France an earnest request that advantage might be taken of this event for connecting the Observatories of Paris and Greenwich. I proceeded without delay to negotiate with the great commercial bodies (the Electric Telegraph Company and the South-Eastern Railway Company) whose assistance was necessary, and whose rights might be affected by such a connection; and by them my overtures were received in the most liberal spirit. To these bodies generally, and to their Superintendants of Telegraph in particular (Charles V. Walker, Esq., for the South-Eastern Railway, and Edwin Clark, Esq., for the Electric Telegraph Company), my most cordial thanks are due, for their adoption of my proposals in all their fulness, and for their hearty co-operation in every part of the work. The Lords Commissioners of the Admiralty at once made provision for carrying out this plan, which had not been foreseen in time for inserting a proper sum in the Navy Estimates. The result is, that four insulated wires are laid in the ground, at depths varying from three to five feet, on a line commencing at the ground-floor of the North Dome (now called the Galvanic Room), across the Front Court, along the centers of the great avenues of the Park to the southern gate in the western wall of the Park, and by the south-east side of the road leading thence across Blackheath to the Lewisham Station; from which point two wires are carried, sometimes on poles and sometimes in grooved boards, to the London-bridge Terminus, where the connections will be made, either with the long Dover wires communicating with the Continent, or with the wires which extend to the Central Telegraph Station. These connections are not yet made.
In my last Report to the Board of Visitors, I brought up the account of the Observatory to 1852, May 18. In the present Report I propose to exhibit the state of the Observatory on 1853, May 22, and to record generally the principal occurrences from 1852, May 13, to 1853, May 22.
I. Grounds and Buildings. – Within the inclosure of the Observatory, nothing has been done requiring the least notice, excepting the commencement of a new set of Plans of the Buildings, &c. Our wants for space, however, continue to increase; and I think that it will be found necessary, very shortly, to construct a new Fire-proof Room for Manuscripts, &c. I propose to erect a building of two stories in continuation of the Eastern Buildings, and to give it a front with pediments similar to those of other parts of the same range.
Beyond our own boundaries, however, there are two things worthy of mention to the Visitors.
The first of these is the repetition of the proposal, by the authorities of the South-Eastern Railway, for carrying a railway through the lower part of the Park. In the last autumn a plan was prepared by them, but there were in it so many points liable to serious objection, that it was withdrawn before it had been presented to Parliament. It is, however, understood that the South-Eastern Railway Company retain the desire of completing this line; and there are many large interests which would receive from it material benefit. The Board of Visitors have long ago been acquainted with my opinion, that, provided due care be taken in the plan of the Railway, the inconvenience which the Royal Observatory would suffer from it is altogether insignificant.
The second point is, the state of our galvanic communications. At the date of my last Report, the principal part of the work for carrying two wires to London Bridge (four having been laid in those parts in which the wires pass underground), was, by the kindness of the South-Eastern Railway Company and the Electric Telegraph Company, completed, but the wires were not so far connected as to be brought into use. Shortly after that time they were brought into daily use. Our prospective wants of galvanic connexions are increasing, and I have lately received the sanction of the Admiralty for the principal measures necessary to establish four complete galvanic lines from the Observatory to London Bridge.
One of the objects which it was proposed at first to effect by making a galvanic connexion with the London Bridge Railway Terminus was, to secure a communication with the Submarine Telegraph, and thus with the Continent of Europe generally, and with Paris in particular. There was reason at that time to expect that the Dover Railway wires and the Submarine wires would be connected. The commercial relations of the companies, however, underwent some change; and ultimately an entire new line of wires has been laid underground from London to Dover, passing over Blackheath. Upon my communicating with Lord De Mauley and the Directors of the Submarine Company, I was assured by his Lordship that every facility would be given by that Company for communication with Paris, provided the connexions were made directly between the Royal Observatory and the wires of the Company. And the Officers of the Company with great courtesy acceded at once to the plan which I proposed, and which is now carried into execution. One of the Company's wires was cut where it crosses Blackheath, and the interrupted segments were continued by branches to a turn-plate which is contained in an iron box fixed in the south wall of the Park. From this turn-plate, a wire is led into the Transit-Circle-Room of the Royal Observatory. By different adjustments of the turn-plate, communications are made between London and Paris, between London and Greenwich, or between Greenwich and Paris. By a most liberal concession of the Company, the key of the iron box is preserved in my custody. The wire has not yet been used for the Greenwich-Paris communication, for reasons which will be explained shortly. In resuming, I may state that we have now the means of communicating with every part of Great Britain and of the Continent.
THE present Report to the Board of Visitors may be understood as recording the general condition of the Observatory on 1854, May 26, and the transactions from 1853, May 22, to that time.
I. Grounds and Buildings. – I alluded in the last Report to the necessity for a new Fire-proof Room. The want of this became so evident that in the last autumn I submitted to the Lords Commissioners of the Admiralty a proposal for constructing one in the present year; and in consequence a sum of £550, applicable to that purpose, has been granted on the Navy Estimates. The plan has been arranged in concert with Lieut.-Colonel Greene, R. E., Civil Architect of the Admiralty; and its general features may be understood as follows:- The Eastern Buildings will be extended, preserving the same general breadth, to the boundary wall of the Observatory grounds. Access will be gained to the lower story by taking the breadth of a passage out of what is now the First Assistant's Room (the East Depot being in future appropriated to the First Assistant), and to the upper story by an internal iron staircase. The stack of chimneys in the middle of the Library will be removed. Several preparations have been made for this work; but, at the present time, ground has not been actually broken.
The support of the quicksilver-trough for the Reflex Zenith Tube is not sufficiently steady: the proximity to the entrance gate rendering it liable to perpetual jars, and the hardness of the brickwork upon which its sand-bed is founded tending, to propagate the tremors. I propose to construct a small building in the angle between the south-western part of the Transit-Circle Room and the south wall of the passage which leads from the Computing Room to the Transit-Circle Room.
These are all the remarks worthy the attention of the Visitors which relate to the interior of the Observatory inclosure. Exterior to it, the following particulars require notice.
The South-Eastern Railway Company declined to urge in the present session of Parliament their plan for carrying a railway through Greenwich Park. This resolution was taken, not in consequence of any representations on the part of the Observatory, but from considerations of private policy.
Four complete galvanic lines are now established from, the Royal Observatory to the London Bridge Railway Station. Three of these are appropriated to specific uses; the fourth is reserved for contingencies.
The date to which the statements of the Report apply is 1855, May 15, and the interval embraced in its historical portion is that between 1854, May 26, and 1855, May 15.
I. Grounds and Buildings. – The Fire-proof Room, to which I alluded in my last Report, has been completed in all essential parts, and in conformity with the plan which I then explained, except that I have not thought it necessary to remove the central stack of chimneys, but to accommodate new partitions to it, leaving it undisturbed. Two sets of slate shelves are erected. The ironwork, however, of the window shutters is not completed, and, in consequence, we have not yet been able to make full use of the room. These, I expect, will be finished very soon.
The new building for the Reflex Zenith Tube has not yet been erected; but the necessary funds are provided, and I hope in the course of the summer to complete it.
In order to avoid the annoyance which we have several times experienced by being compelled to open the ground for laying down or taking up galvanic wires, I have had several channels constructed of masonry, in the places where wires will usually be required.
These are all the occurrences relating to our buildings and grounds which appear to require mention. But, perhaps, it may be proper in this place to allude to another matter in which the Visitors cannot but feel interest. The Tablet upon Halley's Tomb, in Lee Churchyard, had apparently received no repair since it was first erected. It had sustained injury, probably from the sinking of the ground, and the unequal dropping of the sides of the tomb ; probably also from the strains to which it was exposed when it was taken down for the interment of my predecessor, Mr. Pond, in the same grave. On the last occasion of clearing off the moss from the inscription, I found the stone so much injured, that mere repair appeared hopeless. On my representing this circumstance to the Board of Admiralty, and representing also the public character of the tomb (the inscription is in Latin, and is such as belongs properly to a national monument), their Lordships immediately supplied the necessary funds for its restoration. In order to effect this, I commenced by taking a" rubbing " of the inscription, as a guide to be strictly followed by the masons in cutting the new stone; and the new engraving, in regard both to the excellencies of the inscription applying to Dr. Halley himself, and the faults of those applying to his descendants, is a rigorous copy of the old one.
THE Report which I now present to the Visitors applies to the state of the Observatory, on 1856, May 19. The interval between the date of the last Report, 1855, May 15, and that of the present Report, embraces a period of twelve and a half lunations, which is convenient for the exposition of several points in the astronomical history of the Observatory.
I. Grounds and Buildings. – The new building-for the Reflex Zenith Tube, to which I alluded in the last Report, is erected. A well is sunk beneath it, to the depth of ten feet. I shall explain, in speaking of the instrument the purpose and the effect of this well.
In order obtain more room and more convenient accommodation for our galvanic batteries, it has been necessary to occupy the small cellar at the foot of the Octagon Room staircase; and, to bring this into connexion with the rest of the battery basement, a subterranean passage has been made between the basement of the Octagon Room staircase and the basement of the North Dome staircase.
In the Address dated 1855, October 18, which I submitted to the individual members of the Board of Visitors, I stated that I Was prepared to indicate a position for the proposed new Equatoreal I beg leave to point out to them a locality on the map at the south-eastern corner of the eastern buildings, but not actually in contact with the buildings, which I think possesses all desirable advantages. The Equatoreal must be on the third story. As the old carpenter's shop would interfere inconveniently with this erection, I have already built a new carpenter's shop, and made other arrangements which will enable me to clear the ground at a moment's notice.
I HAVE to offer to the Visitors a Report on the condition of the Observatory on 1837, May 23, and on the general history of the Observatory between 1856, May 19, and 1837, May 23.
I. Grounds and Buildings. In regard to the existing buildings, I have only to state that, for convenience of communication, I have cut a passage through the ground story and basement of the Altazimuth Tower, piercing (for the most part) through Flamsteed’s old walls. In doing this, it was found that those walls had at some previous time been greatly injured, so that I deemed it expedient at once to build up a window-opening with the soundest materials, to apply an iron tie to one of the walls, and to make (rood the part anciently injured as well as possible. I believe that all is now in a perfectly firm state. Nevertheless, I now regret that, in building the Altazimuth Tower, I did not pull down the old walls entirely, for the brickwork of the beginning of the last century appears in general to have been wretchedly bad. A very small portion of one ray of the Altazimuth pier was cut away. I shall afterwards mention the effect which this produced.
The other buildings are in good order. A little dry rot has appeared in the Transit-Circle Room, where stucco had been imprudently placed in contact with wood-work, and the joint was exposed to the drainage of water; but it is not important.
The foundations of the new South-eastern Dome have been laid, and I trust that the building will be completed in this summer. It is in the place which I indicated in the last Report, at the south-eastern comer of the Record Room, but not in contact with the Record Room. For explanation of the design generally, I beg leave to refer to the model which the Visitors have seen. I may here state that the local position of the building compelled me to make the entrances into the three separate stories through the middle of the North Pier. A large stove is provided for the lower story, the draft of which passes underground into the chimney of the Record Room; and I expect that this stove, by means of a trap in the first floor, will sufficiently warm and dry the second story. The dome will be drum-shaped, 29 feet in diameter inside, framed with vertical wooden standards upon horizontal curbs, and tied by diagonal iron hooping. It is to revolve on cannon-balls, and to be moved by toothed-wheel machinery carried by the dome, which acts upon a fixed rack of the wall-curb. The observing aperture will be 3 feet wide. The shutters will be two; a vertical wall-shutter, and a nearly horizontal roof-shutter, opening (for convenience of the mechanism) on opposite sides, each shutter opening independently of the other. Each shutter will carry a curved rack, to receive the action of a pinion carried by the solid parts of the dome. For the vertical shutter) I have made this rack jointed, and thereby I have been able to make the shutter flap close to the opening when it is closed, and flap close back to the dome-wall when it is opened, a condition which is not unimportant for preventing the wind from exerting any action to turn the dome. For the nearly-horizontal shutter, I considered that the attempt to secure a shutter-movement of 180 degrees would introduce the necessity for the jointed rack, and would also require a complicated construction of counterpoises; and I have therefore avoided these by causing the shutter, both in its closed and in its opened state, to take a position inclined to the horizon, its angular movement being about 140 degrees ; thus it will scarcely feel the wind, and the inclination will not be visible to spectators below. Other points can be explained orally.
The manuscript plans of the grounds and buildings are altered from time to time, as the changes of the buildings require.
I PROPOSE to include in this Report a record of the principal transactions in the Royal Observatory between 1857, May 23, and 1858, May 21, and a statement of its condition on 1858, May 21.
I. Grounds and Buildings. – In the older parts of the Observatory-buildings the changes made are very small. A doorway at the east end of the principal range of observing buildings, or the east side of the Transit-Circle-Room, which has been repeatedly opened and closed, is again opened, and it now presents (as will be further explained) the advantage of a covered entrance into the Observatory. When the small room for the Zenith-Tube, on the south side of the passage between the Computing Room and the Transit-Circle-Room, was erected, no provision was made for opening the window; and the appearance of the star in observation impressed on the observers the opinion that better ventilation was required. The window has been so altered as to admit of this ventilation, and the observers have no doubt that the image of the star is much improved. The Visitors will remark a change in the north window of the Octagon-Room. An alteration has been made in the exterior of the Altazimuth-Tower, with the view of bringing its appearance into harmony with that of the other buildings of the Observatory. The buildings generally are in good order.
The new South-east Dome has been constructed in exact conformity with the plan explained to the Visitors at their last meeting, and is in nearly all respects ready for reception of the Equatoreal. Its place is at a very small distance from the south-eastern corner of the Record-Room, where there was exactly space enough to allow three passages around it, (the principal passage to the Magnetic Ground, a passage between the Dome and the Record-Room, and a passage on the edge of the Garden), which it was indispensably necessary to preserve. The stove, with underground draft, answers well for warming the two lower stories. The Drum-Dome, whose external diameter is 32 feet, is constructed with vertical standards upon a horizontal curb, tied by diagonal iron-hooping, covered with very thin boarding, and then covered with zinc. In planning this frame, I omitted to notice that a considerable stress is put upon the two principal standards which form the sides of the vertical shutter opening, and between which there can be no diagonal tie, and that in consequence there would be a sensible bending of the jointed curb when one of these standards should bear immediately upon one of the cannon-balls. A long piece of stiff iron curb, passing under the feet of these two standards and for some distance on both sides of them, is prepared, and is at the Observatory; its mounting is deferred for convenience only. I anticipate that it will entirely remedy the inconvenience that I have mentioned. The rack for motion of the dome is fixed to the wall; the machinery which acts on it is carried by the dome, and the person who turns the winch to move the dome is always on the side opposite to the shutter-opening, and therefore sees the object to which the telescope can be directed. The machinery for opening the two shutters is on the same side as the shutter-opening; the jointed rack for the vertical shutter, and the single rack and counterpoise for the horizontal roof-shutter, answer very well. A misunderstanding of a draftsman, which was not discovered till it was too late to remedy it, has left less room between the great north iron support of the equatoreal and the ring of the curb than I designed, and in consequence the winches of the dome and shutter mechanism are compressed more than I could wish. I have not yet arranged all apparatus for fixing the dome, to prevent it from receiving an oscillation from the action of the wind. Other points of interest will be best seen in the building itself.
The passage on the -North side of the East Buildings and the Record-Room, and the approach to the door of the South-East Dome, are protected by a roof of rough glass. The whole of the Astronomical buildings, and the communications between them, and tile approach from the entrance gate, are now under dry cover; with the exception of the Galvanic Room, which it will be difficult to connect with the others in the same way, though it would be very desirable to effect it.
A new principal map of the Grounds and Buildings has been prepared. The detail-plans and sections of the buildings are kept up as changes are made.
THE Report which I have to lay before the Visitors applies to the proceedings in the Royal Observatory from 1858, May 21, to 1859, May 16, and to the state of the Observatory on the last-mentioned day.
I. Grounds and Buildings.-In the buildings of the Observatory anterior to the New South-East Dome, no change has been made and no repair has been required, that calls for the slightest remark. In the fixed building of the South-East Dome likewise no change or repair has been made; but in the rotatory Drum Dome the following work has been executed. The portion of stiff iron curb, to which I alluded in the last Report, has been fixed in its place, and it appears entirely to obviate the unfair flexure of the Dome Curb under the feet of the standards of the shutter-opening. The apparatus for fixing the Dome at four points, to prevent it from receiving oscillation from the wind, has been mounted several months, and answers perfectly well, no movement of the Dome being perceptible even in a gale of wind. It consists (at each of the four places) of a vertical lever somewhat bent, having its fulcrum attached to the inside of the Dome, and its lower point pressing almost horizontally against the external face of the fixed rack of the wall-curb; in the upper part of the nearly vertical lever is an inclined chase, in which acts the pin of a horizontal lever that is pulled down by a weight. When the weight acts on the horizontal lever, the pin slides in the chase so as to press the upper end of the vertical lever outwards, and to press the lower end strongly against the rack, and thus to exert a strong pressure at its fulcrum from inside to outside against the Dome. When the horizontal lever is raised, the vertical lever ceases to touch the rack or wall-curb, and the motion of the Dome is entirely free.
The flat roof of the Dome has shown itself perfectly trustworthy till within the last three or four weeks. Workmen lately engaged on the top have by their treading injured the zinc sheets; and the center of the flat roof having been a little depressed by the weight of the vertical-shutter and its counterpoise and other machinery, and the roof being thus perhaps rendered too flat, the rain has entered in some places. I propose to revise the covering of this roof, with the view of placing sounder metal at a higher angle of inclination.
The internal fittings required for use in observation, such as a partial amphitheatre of fixed seats on the south side, and a travelling quadrantal chair-frame (carrying a sliding chair) to traverse the rest of the floor, as in the Northumberland Equatoreal, are engaging my attention. A fixed curb parallel to the celestial equator has been established, to receive the weight of a board and chair passing through the equatoreal-frame and of the observer whom they support, when observations are made near to the Pole.
The principal want now felt in the buildings is that of a covered passage to the Galvanic Register.
The maps and plans are maintained in good order.
THE rule which I have adopted in several past years, of presenting to the Visitors a Report applying to a period of 12½ lunar months, appears so convenient that I shall retain it on the present occasion. I proceed therefore to lay before the Visitors a Report on proceedings in the Observatory from 1859, May 16, to 1860, May 20, and on the state of the Observatory on 1860, May 20. The usual order will be followed.
I. Buildings and Grounds. – No important change has been made in the buildings, and no new buildings have been erected. It may be convenient, however, to put the following matters on record.
The Visitors will remark that several cabinets and shelf-cases, which for many years have been attached to the walls of the Octagon Room, are now removed. This was a more serious work than the mere verbal terms imply. Some ignorant carpenter, to make place for these insignificant shelvings, had cut through Sir Christopher Wren's cornices and mouldings, and had planed the astragals off from the pannels [panels]; so that it was impossible to remove the obstructive additions without undertaking the heavy work of restoring the cornices, &c. After many years' endurance of the unsightly fixtures, I at length determined at all events to remove them, and in the last autumn (the first time for perhaps half a century), the shelves, &c. were taken down, the cornices, &c. were restored, and the room was exhibited in the form in which the celebrated architect left it. Two cases are still usually kept in the room for convenience, but the walls behind them are perfect, and the cases are not attached to the walls.
Upon the roof of the Octagon Room is planted a pole (erected, at my request, by the London District Telegraph Company) for carrying the open-air telegraph wires, which swing from this point to a similar pole erected on the roof of a house in George Street, far beyond the Park Wall. I shall allude hereafter to the necessity of adopting this system for our galvanic communication.
The roof of the large S.E. Dome has been altered in conformity with the plan explained at the last meeting of the Visitors. The slope of the zinc covering has been increased, and thicker sheets of metal have been used. Since this change was made, the roof has been perfectly tight against rain.
The internal fittings of the large Dome (principally a partial amphitheatre of fixed seats on the south side, a quadrantal chair-frame turning in azimuth and carrying two sliding chairs, and a curb to support a cradle with the sliding chair which it carries for intra-axial observations, with closets for auxiliary instruments, &c.) have been prepared as was contemplated. These will doubtless require occasional changes, as experience in the use of the Equatoreal shall suggest.
When the projecting cornice was constructed at the top of the tower which carries the S. Dome, it was necessary (for safety) to load its inner edge, and two courses of brick were built on it for that purpose. As this erection seemed to obstruct the lower views of the telescope, it has been removed, and, in its stead, plates of cast-iron of nearly the same weight have been substituted. These plates, besides removing the apparent obstruction, have the advantage of binding together the brick-work of the tower-walls.
The want of a covered passage to the Chronographic Room, to which I have before alluded, is still occasionally felt. It will not, however, be easy to supply it.
The maps and plans of Observatory Grounds and Buildings are maintained.
FOR convenience, I have this year included in the period to which my Annual Report to the Board of Visitors applies, 12 complete lunations (instead of 12½ as in several late years). The Report which I have now the honour to offer exhibits generally the state of the Observatory on 1861, May 10, and the proceedings in the Observatory from 1860, May 20, to that date.
I. Buildings and Grounds. – The changes to be recorded, in the interior of our inclosure, are unusually small. I have lately found it necessary to erect some new slate shelves for Manuscripts on the west wall of the Upper Record Room, and some wooden shelves for stores of printed books are fixed in the Lover Record Room.
A change has been made in the direction of the galvanic wires, suspended in the open air, which lead from the top of the Octagon Room to the top of a house in George Street. These wires, as originally placed, passed over a part of the dwelling of' a resident on Croom's Hill. The owner naturally desired to secure himself against intrusion on his rights as proprietor, but expressed the strongest wish to aid in promoting the objects of the Observatory. With this feeling, I did not anticipate the least difficulty in making a satisfactory arrangement. Unfortunately, the business was placed in the hands of solicitors; and it was soon found that all accommodation was hopeless. A lease was offered, but such conditions were attached to it that the London District Telegraph Company declined to take it, that I could not advise the Admiralty to take it, and that I was unwilling to take it on my personal responsibility. Accordingly, the wires were removed, and a new course was adopted for them, by which, in three steps instead of one, we arrive at the same point which was reached before.
I anticipate that in no very long time considerable extension of our buildings will be found necessary, and it is not easy to say where the requisite space can be found. In Flamsteed's time, one half of the nearly-insulated Observatory Hill sufficed for the nascent Observatory. The successive extensions for Bradley, Maskelyne, and Pond, almost occupied the whole peninsula. My additions of the Record Room and the South-East Equatoreal have covered the isthmus. From the peculiar form of the ground, we cannot add buildings on any point nearer than the Magnetic Ground. Yet, with increase of computations, we want more room for computers; with our greatly increased business of Chronometers and Time-Distribution, we are in want of a nearly separate series of rooms for the Time-Department; we want rooms for book-stores; and we require rooms for the photographic operations and the computations of the Magnetic Department. Whatever plan may be ultimately proposed, I presume on the feeling of the Visitors, that the Observatory Hill must never be abandoned as the place where the fundamental Meridional Observations are to be made.
I have lately had a reduced copy of the Observatory Map taken by photography, which I propose to use as basis for an engraved Map, to be attached to some Volume of Observations.
THE interval between 1861, May 10, the date of my last Report to the Board of Visitors, and 1862, May 13, includes the convenient period of 12½ lunations. I have, therefore, adopted 1862, May 13, as epoch for the Report which I have the honour now to offer to the Board.
I. Buildings and Grounds. – As the pressure of the large number of Computers in the ordinary Computing Room began to be felt as a severe inconvenience, I have had the Middle Room of the S.E. Dome fitted up with desks, &c., and the Supernumerary Computers under their Superintendent (Mr. Lynn) are now located there. I have thus been enabled to assign a larger portion of the Computing Room to the Superintendent of Chronometers and Galvanic Time Communications (Mr. Ellis); and nearly the whole of the apparatus of Galvanic Chronometers, Clock Regulators, and Galvanometers, is now collected there. Other parts of the Computing Room are greatly relieved.
For improving and extending the accommodation required for the various operations of Magnetism, Meteorology, and Photography, a new range of wooden buildings is in progress at the S. S. E. extremity of the Magnetic Ground. It will include seven rooms. When these are completed, Struve's Observatory (which was well adapted to its original purpose, but whose place and position are very inconvenient for the present uses of the Magnetic Ground), and the present Dip House and Deflexion House (whose positions interfere with the new plan), will be removed.
The ante-room of the Magnetic Observatory has been lengthened 8 feet. Although the want of the new buildings above mentioned was more pressing, it was found necessary to proceed first with this room, because it was slightly injured by an accidental fire, in the very part in which the alteration was to be made, and the immediate removal of the Computers became necessary. For the operation of naphthalizing the illuminating gas, a new building of zinc, external to the Magnetic Observatory, is in preparation; and thus one of the possible sources of accidental fire will be removed.
The water pipe, from the large main of the Kent Waterworks Company on Blackheath (which is always charged and under heavy pressure), to the Observatory, has been entirely relaid with tubes of 3 inches internal diameter. I took this opportunity of establishing two powerful fire-plugs (one in the Front Court and one in the Magnetic Ground); a stock of fire-hose adapted to the "Brigade-screw" having been previously secured in the Observatory.
I propose in the present year to make some alterations in the stoves for warming the lower and middle rooms of the S.E. Dome.
No new Map of the Grounds and Buildings has yet been prepared for engraving.
Two wires, intended for the examination of spontaneous earth-currents, have been carried from the Magnetic Observatory to the Railway Station in the town of Greenwich. From this point (by the permission of the South-Eastern Railway Company, and with the friendly assistance of their Superintendent of Telegraphs, Charles V. Walker, Esq.,) one wire is to be led to a point in the neighbourhood of Croydon, the other to a point in the neighbourhood of Dartford. Each wire is to be connected at its two extremities with the earth. The angle included between the general directions of these two lines is nearly a right angle. The erection of the wires has been delayed by the tardiness of a manufacturer in furnishing the insulators; but I have reason to think that the whole will speedily be completed.
THE Report, which I had the honour last year to submit to the Board of Visitors, brought up the history of the Royal Observatory to 1862, May 13th. In the Report now offered, I propose to continue that history to 1863, May 17th.
I. Buildings and Grounds. – In the last Report I alluded to several changes of the buildings, as commenced or in contemplation. They have since been entirely carried out. Struve's Observatory, and the former Dip House and Deflexion House, have been taken down. A range of seven rooms has been built near the southern fence of the Observatory Grounds. Of these, No. 1 (reckoning from the East) is considered as an experiment-room; Nos. 2, 3, 4, 5, 6, are appropriated to various operations of photography; No. 7 contains the Deflexion-apparatus and the Dip-Instrument. On the south side of the range, at a small distance, is a long desk for supporting papers pressed between plate-glasses in the process of making photographic copies. Beyond this desk a piece of ground a few feet in breadth is left vacant.
The extension of' the Magnetic Anteroom has been found extremely convenient. It enables me to place several computers under the immediate inspection of the Magnetic Superintendent. If this extension had been made a few years ago, the magnetic reductions 1848–1857 might have been effected with a great diminution of expense, and, in some respects, in a more satisfactory manner.
The exterior naphthalizing house has been completed, and is in constant use; and contributes to convenience and safety in the degree which was contemplated.
The stove in the lowest room of the S.E. Dome, whose flue was led by underground passage into the chimney of the Record Room, though perfectly successful as regarded draft, &c., did not give a sufficient volume of heated air to the middle room for the comfort of computers in cold weather. I have therefore had a stove planted in each room with rising flue ; these flues are led through the wall of the staircase, and, scarcely remarked by the eye, pass to the roof of the Record Room. The stoves effect their purpose of warming the rooms extremely well.
A Map of the grounds and buildings in their present state has been nearly prepared for engraving, but I have not yet completed it sufficiently to place it in the engraver's hands.
The wires for observation of spontaneous magnetic earth-currents have been mounted, extending from the Royal Observatory along the poles of the South Eastern Railway, one to a point in the neighbourhood of Croydon, the other to a point in the neighbour hood of Dartford. They are insulated with great care. I shall in the course of this Report again allude to them.
The Visitors are aware that the project of carrying a Railway in a tunnel through the lower part of Greenwich Park has this year been revived. Three plans were proposed, by three different companies; two of them are withdrawn, but one (that of the London, Chatham, and Dover Railway Extension) is still pressed. On this subject I may say briefly that I believe that it would be possible to render such a railway innocuous to the Observatory ; it would however be under restrictions which might be felt annoying to the authorities of the Railway, but whose relaxation would almost insure ruin to the Observatory. And it is to be remarked that, for this very reason, the communication between Woolwich and London was, some years ago, carried round in the detour by Lewisham; that, if connection between Woolwich and Blackfriars is required, a junction can easily be made either in the Ravensborne valley (which makes connexion both with Blackfriars and with the Crystal Palace) or at Gravel Lane; and that a very small expense would independently connect Woolwich with Greenwich. The passage through the Park is now therefore actually unnecessary.
IT has been my rule, in framing my Reports to the Board of Visitors for several years past, to adapt them to periods bounded at the beginning and at the end either by the beginning or by the middle of a lunation. The Report which I have the honour now to place before the Board applies to the period of twelve and-a-half lunations, from 1863, May 17, to 1864, May 20.
I. Buildings and Grounds. – Only one chancre has been made in the Astronomical Buildings. It had long been remarked that the ventilation of the South Dome (in which the Altazimuth is mounted) was insufficient. I have therefore opened two windows into the room, one on the South and one on the East side. The south window is not often used, and is in fact at the present time blocked by a shutter; but the east window is almost perpetually open, partly by understood regulation and partly because the external thermometer is fixed without it; and the temperature of the room is now in an excellent state.
The North Dome (formerly called the East Dome or North-East Dome) does not exclude the rain so perfectly as it ought. Instructions have been given to the proper workmen for its examination, and it may possibly be made water-tight by the time of the Meeting of the Board.
Two piers have been built in the Front Court for the support of instruments which I expect Mr. Otto Struve to bring, to be used in observations connected with the Great Arc of Parallel. It was necessary to dig to the depth of 12 feet, to obtain a satisfactory foundation for the piers. A portable observatory is to be erected over them in some part of the approaching summer.
In a very heavy squall which occurred in the gale of December 2 of last year, the stay of the lofty iron pillar outside of the Park Rails, which carried our telegraph-wires, gave way, and the pillar and the whole system of wires fell. By permission of the Department of Her Majesty's Parks and Public Buildings, I was enabled to select a new position within the Park, and thus to attach the wires to a much shorter wooden mast. On the last day of the year, communication was again made perfect.
An important alteration has been made in the Magnetic Observatory. For several years past, various plans have been under consideration for preventing large changes of temperature in the room which contains the magnetic instruments. At length, I determined to excavate a subterraneous room or cellar under the original room. The work was begun in the last week of January, and in all important points it is now finished. The ground was cut down on all sides in the plane of the inner surface of the former walls, and within this space a 9-inch wall was built all round, so that the transverse dimensions of the room are less by 18 inches than those of the former room. Bricks were selected which were almost free from magnetism. Tile room is illuminated when necessary by three well-windows, facing the South; these can be covered by yellow glass, or by wooden shutters, and can otherwise be blocked.
It can be warmed by a gas-stove, and lighted by gas-lights. Ventilation is provided by a large copper pipe leading to the ventilating-cowl of the upper room (no longer required for the upper room), through which pipe the warm stove-pipe is led nearly to the top. Drainage is effected by a pump in the ground outside of the building, about 20 feet distant from the eastern arm of the building. The building has been somewhat delayed by the illness of the Superintendent of Works, and also by the circumstance that the walls dry slowly. The reading of the atmospheric dew-point, at this season, is sometimes higher than the mean temperature of the ground, which is the temperature of the walls. It seems probable that the stove will be required more frequently in summer than in winter. On the erections for carrying the instruments, I shall speak hereafter.
The Map of the Grounds and Buildings has been engraved; it is accompanied by a description, with historic references, Which might have been more complete if at the time of writing I had been possessed of the documents to which I shall soon allude. The whole is finished, but the circulation, with that of other parts of the Astronomical Volume, is delayed for a reason to be mentioned hereafter.
No steps, so far as I am aware, have been taken in the present year, for urging the proposal of a Railway through Greenwich Park.
IT is convenient on the present occasion to limit my Report to the period commencing 1864, May 20, and terminating 1865, May 10. The arrangement which I have maintained for many years is adopted without alteration.
I. Buildings and Grounds. – No alteration whatever has been made in the Buildings ; unless I may include in that term the excavation of a hole in one of the walls, for the fixing of an iron safe. The whole of the external wood-work of the buildings was repaired and painted shortly after the last visitation of the Board.
The defect in the North Dome, to which I adverted in the last Report, has been made good. It was necessary to re-make the Dome-shutters entirely.
The two piers which are built in the Front Court, as well as a third pier built in the Magnetic Ground, having been used nearly in the way proposed for the observations connected with the Great Arc of Parallel (as will be hereafter mentioned), the portions of the piers which projected above the ground have been taken down; their capping-stones being left at the surface of the ground, with an inscription engraved on each for its identification.
Our telegraphic communications of every kind were again destroyed by a snow-storm and gale of wind which occurred on January 28, and which broke down nearly all the posts between the Royal Observatory and the Greenwich Railway Station. They were restored after a time, without alteration of plan, (except in the instance of the wire appropriated to the Electric and International Company, which, by request of that Company, and at their expense and under their superintendence, was placed underground,) but with general renovation.
In my last Report I described the steps which had been taken and the further arrangements which I proposed to make, for forming and adapting to use the subterranean room of the Magnetic Observatory, now called the "Magnetic Basement." Everything has been carried out as was then planned; and I believe with perfect success. Though it is still necessary sometimes to wipe a little moisture from the walls, yet the air of the room is usually very dry. The extreme difference of temperature between summer and winter is about 6º, the greatest variation in any one day about 2º;the temperature never differs much from 60º; (all in Fahrenheit's scale).
The only change of Buildings which I contemplate as at present required is the erection of a fire-proof Chronometer Room. The pecuniary value of Chronometers stored in the Observatory is sometimes perhaps as much as 8,000 l. I do not see that this can be done in any other way than by retaining the present room (the room above the principal Computing Room), making fire-proof floor and ceiling, and stripping the old pannelling [panelling] from the walls.
Several small repairs of buildings and fences, and some interior painting, lately sanctioned in the Navy Estimates, will shortly be put in hand.
Among the buildings of the Royal Observatory, I may now class the Time-Ball-Tower at Deal. On occasion of the sale of the Navy Yard at Deal, the Time-Ball-Tower, at my representation to the Admiralty, was specially reserved; and, as there is now no competent resident authority for its superintendence, it is placed generally under the care of the Astronomer Royal. Beyond this announcement I have no special remark to make.
The Visitors are acquainted with the proposal lately made for carrying a Railway through Greenwich Park. Such a proposal now assumes a character differing, from what it ever had before. When in 1835 the scheme was first brought forward, it was supposed to be intended to only convey passengers from London Bridge to Gravesend. Now, in 1865, it would bring the whole personal and commercial traffic from every part of the North of England and from London to every part of Kent. It is also proper to remark that the shake of the Altazimuth felt in the earthquake of 1863, October 5, when no such shake was felt with instruments nearer to the ground, (an experience which as I have heard on private authority, is supported by observation of artificial tremors), gives reason to fear that, at distances from a railway which would sufficiently defend the lower instruments, the loftier instruments (as the Altazimuth and the Equatoreals) would be sensibly affected.
The Report which I last presented to the Board of Visitors was brought up to 1865 May 10. The present Report terminates on 1866 May 14, applying to the state of current business on that day, and to the principal occurrences between the two days specified. The Heads of Report are the same as those which I have adopted for many years.
I. Buildings and Grounds: –
No alteration has been made to the substantial building, and none but the most ordinary repairs have been executed.
On 1865 May 23, a thunder-storm of great violence passed very close to the Observatory. After one flash of lightning, I was convinced that the principal building was struck; and while on my way to seek for marks of injury, I saw another flash strike Greenwich Hospital. No very certain marks of the first flash were seen upon the lofty building of the Observatory; but several galvanometers in the Magnetic Basement were destroyed. Lately it has been remarked that one of the old chimneys of the principal building had been dislocated and slightly twisted, at a place where it was surrounded by an iron stay-band led from the Telegraph Pole which was planted upon the leads of the Octagon Room; which stay-band (intended only as a guard against accidents) had never sustained and could never have exerted any mechanical force. The top of the Telegraph Pole was furnished with seventeen sharp spikes; and was connected with the iron stay to the chimney, an iron conducting-rod to the leads, two iron wires more than 400 feet long to the Magnetic Basement, and nine iron wires more than 800 feet long, across the Park. It appears therefore that the electric current was divided into at least two courses, namely by the iron stay to the chimney and by the iron wires to the Magnetic Basement. It also seems probable that the cluster of sharp spikes had attracted the electricity in one shock, instead of drawing it off gradually. The Telegraph Pole has lately been removed.
The snow-storm and gale of wind on 1866 January 11, which caused so much interruption in all the telegraphs of the south of England, completely destroyed the open-air telegraphic communications of the Royal Observatory; and our partial telegraphic service has since then been carried on through some spare wires accompanying that of the Electric and International Company to which I alluded in my last Report. On consideration of the serious interruptions to which we have several times been exposed from the destruction of our open-air Park-wires and street-wires, I have made an arrangement for leading the whole of our wires in underground pipes as far as the Greenwich Railway Station. Repeated delays have occurred, such as are almost unavoidable where the interests of several companies are concerned; and finally, it has been found impracticable to reinstate all our communications until a new subaqueous cable shall be laid across Deptford Creek. At present therefore the galvanic lines for the earth-currents, and those for occasional communication with an Admiralty line, are interrupted. On completing these lines it is proposed to dismount the turn-plate which is intended for Admiralty communication, from the Gothic House at Deptford, and to fix it at the Deptford Station where the South Eastern Line crosses the Admiralty Line.
The Magnetic Basement has been perfectly dry, except on the following occasion. I must premise that, for conveniently removing the large quantities of water used in the photographic operations, a pump is established in a dry well about 30 feet outside of the Magnetic Observatory, by which the water is thrown at once into a subterraneous drain. In the late spring, much soil-water collected itself in this well, and oozed by the side of the suction pipe into the Basement. The pump has now been fitted with the means of exhausting the dry well, when necessary. The ground, also, in the neighbourhood of the Magnetic Observatory has been hollowed into such a form as to throw the rain water to a distance. I anticipate that the ground will be made drier than it ever was before.
The temperature of the basement has been maintained as near as possible to 590 Fahrenheit. For this purpose, it is necessary sometimes to use the warmth of the gas-stove, sometimes to shade the windows externally and to sprinkle the upper floor with water.
The Tower at Deal for the Time-Signal-Ball has been properly inclosed and fitted for the residence of the Ball- Attendant.
I alluded in my last Report to the demand for a fire-proof Chronometer Room; and to the scheme of rendering the present room fire-proof. With the sanction of the Board of Admiralty, I have had some consultations with the Admiralty Surveyor of Buildings on this proposal. So many difficulties, however, appear, that for the present I withdraw that plan. But it is desirable to keep the matter in view, both for the purpose of insuring the safety of the Chronometers, and for the purpose of gaining room. I believe that it will be practicable, by withdrawing a number of Chronometers from rating or winding, to store them in such a manner that the present pressure for room may be relieved, but it is desirable that we should not feel ourselves driven to that resource.
The roof of the old staircase to the Octagon Room (the original roof, I believe), has been found to be in a very bad state, and I propose to restore it in the approaching summer. In contemplation of this, I have deferred some small repairs to the staircase-walls, &c.
The establishment of the proposed new Collimators or Reversed Telescopes in the Transit Circle Room will require small alterations in the north and south walls of the room, the new telescopes being longer than the old ones.
The subject of Railways approaching the Royal Observatory still requires notice. Between the date of my last Report to the Visitors and the last Meeting of the Visitors, the Chairman (Sir John Hanmer) of the Committee of the House of Commons to whom the " Greenwich and Woolwich Line" of the South Eastern Railway was referred, with some Members of the Committee, and with the Secretaries and Engineers of the Railways concerned, together with the President of the Royal Astronomical Society, came to the Royal Observatory, inspected the ground, and (after receiving the Report of some experiments for which my First Assistant and another Assistant were sent to Ireland), finally assented to the adoption of a line which I indicated, passing between the buildings of the Hospital Schools and the public road to Woolwich. This line has been promoted in the present Session of Parliament, and, so far as I am aware, proceeds in its official course without difficulty. Connected with this is the proposal of the London, Chatham, and Dover Railway. That company, two years ago, received powers to make a railway up to the wall of Greenwich Park ; but in the present Session they applied for a bill to withdraw that railway, and, instead, to make a junction with the South Eastern line above mentioned. Their bill has been rejected, not on the merits of the case, but on some point of Standing Orders. I regret that this final settlement of a long troublesome matter has been interrupted, and I hope that the interruption may produce only a short delay.
IN order to allow myself sufficient leisure for careful reference, in preparing this Report, 1 have made it to terminate on 1867, May 3. The interval between the times to which the last Report and the present Report apply is twelve lunations. The general plan of the Report is the same as that which has become customary in my Reports to the Visitors.
I. Buildings and Grounds: –
Commencing with the original or Flamsteed's building, I have to state that the roof of the old or exterior staircase has been taken down and entirely replaced. The old roof was found to be in a very bad state; some of the old beams had, at sonic distant time, been found rotten, and had been patched with side-pieces; some were now found so rotten that they broke on being carried away. In restoring the roof, the old form has been preserved as closely as possible. The interior work of the staircase has been renovated and painted; and the closet on the landing, which I believe had been constructed for Dr. Maskelyne's footman (the dwelling house being then very small), has been taken away. The space occupied by the windlass and cylinder of the Time-Signal Ball has been inclosed by a hinged partition.
When geodetic operations were commenced in 1787, for connecting the observatories of Greenwich and Paris, a double truss was constructed, spanning over the roof of the Octagon Room and bearing upon its walls; and on this truss Ramsden's theodolite was supported above the center of the roof. The observing-hut or cabin which covered it was planted on the flat roof itself. [Airy is in error here: Roy mounted the theodolite above the transit circle and not on the Octagon Room roof. In was in a later survey in the early 1820s that Captain Kater mounted a theodolite for the first time on the roof of the Octagon room an offset from the transit circle being subsequently applied. It can be probably assumed that the hut dates from that time.] The truss, being rotten, was removed by me about 1837, but the cabin remained, and had by degrees been loaded with various instruments. As I began to fear for the safety of the flat roof, I have had a single truss constructed near the south side of the roof, spanning from the south-east wall to the south-west wall; and one side of the cabin is carried by this truss, the other side bearing directly on the south wall. In this way, the pressure on the flat roof is entirely avoided.
On occasion of making the alterations in Osler's Anemometer, to which I shall hereafter allude, the roof the North-Western Turret was thoroughly examined and repaired.
In the central or Bradley's mass of buildings, from the Manuscript Room (West Quadrant Room) to the Record Room, nothing has been done, except the hinging of the lower wood-walls of the North and South openings of the Transit Circle Room, to give facilities for the use of the lengthened Reversed Telescopes or Collimators.
The room above the Principal Computing Room is at present devoted to the custody and rating of 'Marine Chronometers, the property of the Government, or on competitive trial. In the event of making the changes in the building of the South-East Dome to which I shall immediately allude, the chronometers will be removed from this room, and it will be occupied by Computers.
In the South-East Dome and the two stories of building below it, no alteration has been made; but the following alterations have been sanctioned by tile Board of Admiralty and by the House of Commons. By proper alterations of the three floors, the staircase, and other portions of the building, every part below the wooden dome is to be made fire-proof. Then it is intended that the Chronometers shall be transferred to the middle room; and the Supernumerary Computers, who now occupy that room, will in future work in the room above the Principal Computing Room. In this manner, besides attaining the object which I have long had at heart, the giving security to the Chronometers, I shall at the same time give security to the South-East Equatoreal, and shall place the Supernumerary Computers in more convenient proximity to myself and the Assistants.
The nearly flat roof of the rotatory dome has frequently become leaky. This has at length been traced to an injudicious connexion of the zinc at the top with that of the sides; a fault for which I am in part responsible. I now propose, without making any modification in the movements of the Upper Shutter, to make an alteration in the Roof, which will shoot off the water more rapidly than at present, and in which no connexion will exist between the zinc-sheets of the roof, and the zinc-sheets and other parts of the dome-walls.
In the Magnetic Observatory, shelves have been erected in the southern arm, for stowage of the Magnetical and Meteorological Publications of the Observatory.
The Magnetic Basement has been perfectly dry, and its walls are in a very good state. Considerations of temperature and of photogenic action have shown that greater ventilation was sometimes required; and I have therefore fixed a larger ventilation-tube (passing through the upper room) with section about double of that formerly used, and with cowl of corresponding dimension. With this tube, and with means of partially closing the aperture, and with the use of the gas-stove, and with the ordinary management of windows and shutters, command of temperature and of photogenic action is practically perfect.
The ground plan of the building was accommodated to the direction of terrestrial magnetism in 1837. In consequence of the N.W. and S.E. direction of Magnetic Declination, the south-easterly re-entering angle of the building, to which the Horizontal Force Magnetometer is near, receives less of the Sun's rays than are received by the south-westerly re-entering angle, to which the Vertical Force Magnetometer is near; and in consequence of this, the latter instrument is usually between 1º and 2 º warmer than the former. I propose to shift the gas-stove, which at present is equidistant from the two instruments, a little nearer to the Horizontal Force Magnetometer.
Much trouble was caused in the late winter by the deposit of crystals in the copper gas-pipe leading to the naphthalizing-house. It has been changed for an iron pipe, at a greater distance from the Magnetic Observatory. Subsequently, trouble has arisen from water in the pipes; but this, as appears to be certain, is deposited by the gas.
No alteration has been made in the Magnetic Offices, or in the Sheds or other out-buildings.
Our eight telegraph wires are now led (by arrangement with the Electric and International Telegraph Company) underground to the Greenwich Railway Station, and thence on the poles of the South-Eastern Railway, and by a cable under Deptford Creek. At Deptford Station, by the liberal permission of the South-Eastern Company, a turn-plate is fixed, into which two of our wires are led; and from the Admiralty wire which passes through the High Street of Deptford, a loop is led into the same turn-plate, so that the Admiralty loop can practically be extended into the Royal Observatory, and can, when necessary, be interrupted there. I have been desirous of maintaining this command of wire, with the hope that I may yet have occasion to use it for the transmission of signals to Devonport in reference to the exhibition of time-signals on the Start Point, or in other directions for similar purposes.
The proposed line of Railway through the town of Greenwich and on the north side of' the Hospital Schools, promoted by the South-Eastern Railway Company, which I considered unobjectionable in reference to the interests of the Observatory, received the entire sanction of the Legislature in the summer of 1866. But no action is yet taken on it, and I understand that no immediate action is contemplated. The London, Chatham, and. Dover Railway Company have made no new application for sanction of their line of junction with the South-Eastern Company's line (rejected last year on a point of Standing Orders). It seems not impossible that in a few years we may have to fight the whole battle over again.
I have the honor to offer to the Board of Visitors a Report, on the general transactions in the Royal Observatory, from 1867, May 3, (the date at which the last Report terminated,) to 1868, May 6, and on the state of the Observatory upon the last-mentioned day.
I. Buildings and Grounds: –
No repair or alteration has been made to the original building of Flamsteed. But in one of the small rooms attached to it, forming a part of my dwelling house, it is proposed in the present summer to raise the roof, for the purpose of giving better ventilation to the room.
The room above the Computing Room is still occupied by the Admiralty Chronometers and Trial Chronometers. I hope in no long time to remove them to the South-East Dome, as I shall shortly mention.
In the principal Library, I have placed an iron air-stove; the chimney-grate being found in many circumstances useless for warming the room.
In the Lower Record Room I propose to fix, on the unoccupied walls, additional sets of slate shelves. And I hope soon to remove the stores of printed books, which at present occupy space that was not intended for them, into another place of deposit, to which I shall soon allude.
In the South-East home, the alteration proposed last year for rendering the building fire-proof has been completely carried out, under the superintendence of the Admiralty Director of Works. For the wooden staircase, an iron staircase has been substituted. For the two upper wooden floors, there have been fixed floors carried by radiating girders and cross joists of wrought-iron, whose flanges support light spars which are heavily plastered above and below, and finally carry floors of tiles; a construction which, as I understand, is approved by the best builders of the present day. The lowest floor is paved with flagstones. For the middle room, which is to be appropriated to Chronometers (giving us much more space than we command at present), the requisite tables and shelves, with a Chronometer-oven larger than that which we use now, are in the workmen's hands, but are not yet mounted. In the lower room, I have separated a small space, by a partition of corrugated iron, to be used as Chronometer Office. When all these are ready, the Chronometers will be shifted to this room; and the room vacated by them (above the Computing Room) will be occupied by Computers.
The alteration of the roof of the rotatory dome, to which I alluded in my last Report, has been made, and the leakage has been effectually stopped. There have been occasional small chinks in the upper shutter, &c., as in all places covered with metal.
Of the Magnetic Observatory, I have to describe only a small alteration of flue-pipes in the Basement. I called the attention of the Visitors, in my last Report, to the circumstance that the S.W. (astronomical) part of the Basement was usually warmer than the E. part. To remedy this, first, the gas-stove was shifted in an easterly direction, but its effect was insufficient. Mr. Glaisher then suggested that by providing a proper flue for the gas-burner which illuminates the Horizontal Force Scale, and maintaining this light more constantly instead of the gas-stove, a good equilibrium of temperature might be maintained. This was done, with perfect success; there is no certain difference between the temperature of the two ends of the basement. At the same time, by continual attention to the sources of warmth and ventilation, the temperature of the whole has been maintained in a state of uniformity which à priori I should scarcely have thought possible. The great summer beats arc now our only enemies, and not very formidable ones.
A proper flue has been provided for the lamp of the Vertical Force scale.
The gas-pipes in this department are usually washed out every week. This operation is attended with the inconvenience of extinguishing the gasburner on the mast (which, as I shall mention, I supposed would at this time be no longer wanted).
No alteration has been made in the Magnetic Offices. A small shed, called the "Telescope-Stand-Shed," has been taken down to make room for the following building.
In my last, Report, Article VIII., I suggested, as a possible subject for future consideration, the providing of some extraneous room in which our accumulation of printed Productions of the Observatory might be deposited. I have now selected a place on our own grounds, at the south-eastern corner of the inclosure, where a building can be erected, about 35 feet in length and 13 in breadth, its back ranging with the back of the Great Shed, and its end ranging with the back of the Magnetic Offices, a sufficient passage being left at the east end of the Magnetic Offices. I propose to fit up this repository by the simple arrangement of six racks of book-shelves, with three alleys between them, each alley having a separate door at the south end; the illumination being given by sky lights made of thick glass plates, of the same size as slates, and intermingled with the slates of the roof. The materials removed from the old floors of the South-East Dome will supply to a considerable extent the wants of this building.
It is an inconvenience attending this plan, that the free draught, of air over our grounds and past our thermometers will be in some measure interrupted. The authorities of the Observatory must look forward to an extension of its grounds; a thing which cannot be effected without difficulty.
Our subterranean telegraph-wires were all broken by one blow, from an accident in the Metropolitan Drainage Works on Croom's Hill, but were speedily repaired. Two of the wires, which I have maintained and still maintain with the hope of application to the service of Time-Signals at Devonport and the Start Point, being at present unemployed, I propose to make use of them (with others) for a time, in a new modification of the Earth- Current-experiment, to be mentioned below.
The line of Railway through Greenwich, which, it was believed, was arranged in a form that met the wishes of all parties, and which had received the sanction of all the branches of the Legislature, has now (I believe) been abandoned. I can scarcely doubt that an equivalent line, possibly with features more objectionable to the Observatory, will at some time be proposed; and the disputes, which have already lasted more than thirty years, will be again roused.
THE Report on the Royal Observatory (the thirty-fourth in numerical order), which I have the honor now to submit to the Board of Visitors, is intended to give an account of the state of the Observatory on 1869, May 10, and of the general history of the Observatory from 1868, May 6, to 1869, May 10.
I. Buildings and Grounds:–
The roof of one of the newest rooms of the dwelling-house, adjoining the original building of Flamsteed, has been raised, as was anticipated in the last Report, and the room is greatly improved.
The small Safe Room of the Observatory (a portion of the original Quadrant Room) had, from various changes, become very inconvenient for Observatory use. I have now removed the manuscripts which it contained into the Record Room, and have appropriated it to the preservation of Books and Papers, partly my own, partly related to local institutions. By the existing arrangement of doors, &c., the room has in fact been always more closely connected with the dwelling -house than with the Observatory.
The Chronometers were removed from the room above the Principal Computing, Room to the middle story of the South-East Dome, at the end of July 1S68 ; and the room was fitted with desks, &c., and is now used as Second Computing Room for the Supernumerary Computers.
It has been found desirable to keep in readiness for use when required a framed stage, which can be planted upon the staircase-roof of the South-East Dome, and which then gives access to every part of the exterior of the revolving drum-dome. For convenient preservation of the parts of this stage, a small shed has been fixed on the leads of the Library.
The air-holes for admitting air to the stove by which the Record Room is warmed were open to the north. In consequence of this position, it was almost impossible to obtain a proper in-draft of air, when the damp S.S.W wind was blowing, and when drying heat was most wanted. I have lately pierced the south wall, in order to give air-entrance on that side.
The additional sets of slate-shelves have been fixed in the Lower Record Room. And I hope that, before the presentation of this Report, the stores of printed books which now incumber that room will have been transferred to the new depôt on the newly-added ground.
The channels for conveyance of the galvanic wires across the Front Court (connecting the Computing Room, the Altazimuth, the Transit-Circle, the Transit-Clock, the new Chronometer-Room, the S.E. Equatoreal, and its Chronometer, with the Chronograph, the Normal Mean Solar Clock, the Time-Signal-Ball, External Clocks, and External Time-Signals) have been considerably enlarged.
The Middle Room of the South-East Dome is now completely fitted up as Chronometer-Room, with ample accommodation of Tables for Chronometers, with large Chronometer- Oven, and with exposed railed outhouse for chronometers to be placed in the open air. The scale of all these permits us to place the chronometer-boles, if we think fit, with their lids open, and with the box-fronts towards the observer. The adjustment of the heat of the oven is easy and accurate.
There is nothing to remark on the Observing Room of S.E. Equatoreal, except that we were annoyed for a time with friction of the upper shutter, which however was soon remedied.
On the Magnetic Ground, a shed which has been used as temporary observatory is at present planted as a shelter for detached telescopes and telescope-stands. I intend, as soon as the Great Shed shall be removed (to which I shall soon allude) to erect a shed in its place, for more convenient protection of these telescopes and stands.
No alteration has been made in the Magnetic Observatory. The cautions which we have learned to take, and which are made effective by the incessant attention of Mr. Glaisher, have enabled us to control the temperature generally without actual change of the walls of the building. Still we find that the effect of the sun's radiation in the south-west re-entering angle will sometimes make itself sensible; and at the present time a large wooden screen is mounted there to ward off the heat.
At the last Visitation, I had the great advantage of pointing out, on the spot, to the Hydrographer and the Director of Works of the Admiralty, the too close proximity of the various buildings on the Magnetic Ground, and the increasing necessity for an extension of the domain of the Observatory. Fortified by the concurrence of their opinions, I brought the subject before the Board of Admiralty and the Commissioners of Her Majesty's Works and Parks, &c., suggesting that the eastern boundary of the grounds should be extended 100 feet, that the southern boundary should there be set off at right angles, and that the western boundary should be continued to meet it. My representations were most favourably received by both offices; and, with no greater delay than the nature of the business and the season of the year necessarily produced, the Warrant for the annexation of this space to the Observatory grounds received Her Majesty's Royal Signature on 1868, December 8. The new depôt for the Printed Productions of the Observatory, to the proposed plan of which I alluded in my last Report, was in progress of construction; but, in anticipation of the extension of territory, I had so arranged its frame that it could be transported to a new position with little trouble. The new ground was extremely uneven, but, by a considerable amount of earth-work, and by erection of substantial retaining walls in some parts, I have been able to arrange it in two horizontal planes at different elevations. The depot is transferred to its position in the new ground, and its internal fittings are advancing. The foundations and underpinning for the Great Shed are completed, and as early as possible, but probably not before the assembly of the Visitors, it will be shifted from its present place on the Magnetic Ground to that new site. The positions selected for both these buildings are close to the new southern boundary. Great advantage will be gained to the Magnetic Ground, and great freedom for many purposes, by this extension of our inclosure.
No important interruption has taken place in our external galvanic communications.
The courses of our wires adapted to the registration of' spontaneous terrestrial galvanic currents have been entirely changed. The lines to Croydon and Deptford are abandoned ; and for these are substituted, a line from Angerstein Wharf to Lady Well Station, and a line from North Kent Junction to Morden College Tunnel. At each of these points the communication with earth is made by a copper plate 2 feet square. The straight line connecting the extreme points of the first station intersects that connecting the two points of the second station, nearly at right angles, and at little distance from the Observatory; but great length is added to the wires (apparently with no inconvenience) by the necessity of following the railways to their junction in order to lead the wires through the registering apparatus in the Observatory. The arrangement of wires could not have been effected, but from the circumstance that we had two wires disposable which I hope at some time to use for signals on the Start Point, and also two spare wires. A map of the courses of these wires will be exhibited to the Visitors.
I continue to maintain in good order the inclosing fence of the Obelisk on Chingford Hill. As a meridian-mark for the transit-instrument, this pillar is now useless; but I attach importance to the preservation of the object which, taken in conjunction with the central opening of Bradley's Transit-Room (now the Astronomer Royal's Official Room), defined the first meridian of the Trigonometrical Survey of Britain. It is now backed by trees of Epping Forest, and, when it is to be used, it will be necessary to attach to it a lofty pole.
The question of railway through Greenwich is still unsettled. After abundant consideration of this question, remarking that there is no necessity for carrying London-Woolwich passengers through Greenwich, that the construction of the Great Sewer will render a thorough railway far more annoying to the Town of Greenwich than it might have been formerly, and that every facility for easterly communication may be given to Greenwich and to Deptford at very small expense, I am satisfied that, independently of any consideration of the Royal Observatory, it would be most advantageous to all parties (including the South-Eastern Railway Company) to lay aside all thoughts of a line through Greenwich.
THE view of the state of the Royal Observatory presented in this Report applies to its general condition on 1870, April 30. The interval of time included in its record of work done is the space of twelve lunations, beginning on 1869, May 11, and ending on 1870, April 30.
I. Buildings and Grounds:–
In the Astronomical Department the modifications introduced have been very small.
The ground-floor room in the East Buildings facing the north, now looking into the Glass Passage, which was lately called the East Depot, and was used for deposit of printed volumes, is now appropriated as an ante-room to the Supernumerary Computers.
All printed books have been removed from the Lower Record Room, and its shelves are occupied by manuscripts. It is estimated by Mr. Carpenter that an additional length of ten feet of shelving is required every year; and in a few years some additional shelves must be provided.
In the Equatoreal Room of the South East Dome, the friction of the roof-shutter, to which allusion was made in my last Report, returned in a troublesome degree. A small portion of a plate of iron in the roof was cut away, and the annoyance has ceased.
A temporary rough bridge or gallery has been carried from the north-west window of the Equatoreal Room to the leads above the Library. The object of this is to give facilities to Mr. Stone's observations on the radiating heat of the stars. The thermopile is carried by the telescope of the Equatoreal; but it was found impracticable to use the galvanometer in the proximity of so much moving iron. Wires were, therefore, led from the thermo-pile to the Library, where the galvanometer could be efficiently used, and the bridge was constructed to give rapid transit from the telescope to the galvanometer.
An iron door for the Equatoreal Room is in preparation, and will probably be mounted before the presentation of this Report. Its intention is to cut off one of the possible inlets of fire into that room.
In the first division of the Magnetic Ground (now called the Magnetic Court), the Occasional Observatory has been removed to the South Ground, as will shortly be mentioned.
No alteration has been made in the upper rooms of the Magnetic Observatory. But the staircase which leads down into the Magnetic Basement, and which was inclosed in the upper story by pannelled sides and a door, has now also been inclosed in the lower story by pannelled sides and a door. We have strong reason for believing that this arrangement contributes sensibly to cut off the communication with the changing atmosphere of the upper regions, and thus to maintain uniformity of' temperature in the Basement.
Signs of dry rot were lately remarked in the floor of the Basement. As the floor supports nothing important, the injury is limited to a possible giving way of some planks; none, however, has yet occurred. To promote ventilation for the future, I have removed portions of some of the planks so as to leave long narrow chinks across the room, which give very free passage of air, without inconvenience to the feet.
The Earth-Current self-registering apparatus has hitherto been placed in the western arm of the Basement, nearly in contact with its south wall, and under the staircase. We are commencing (and shall probably have finished before the Visitation) to transfer this apparatus to the eastern arm of the Basement, to be nearly in contact with the south wall there. The apparatus will thus be more accessible; and it seems probable that the removal of the lights from the west to the east end will tend to destroy the slight elevation of temperature which has usually been remarked at the west end. The immediate motive for this shift was, to give facility for the introduction of mechanism for imprinting simultaneous photographic hour-lines on the registering barrels, of which I shall speak hereafter.
On the external east wall of the south arm of the Magnetic Observatory, a small shed has been erected, for receiving the cushions of the Basement well-windows.
In the Magnetic Ground (the space between the Magnetic Observatory and the Magnetic Offices) a shed seven feet high has been built expressly for the shelter of detached telescopes and telescope-stands. By the substitution of this low shed for the Great Shed, and by attention to the tree-foliage, the ventilation of the space has been improved.
In the South Ground, the Great Shed and the Depôt for Printed Publications were erected shortly after the last inspection by the Visitors. Anxiety was expressed by some persons in regard to the risk of damp to the books inclosed in a wooden shed without artificial warmth. Mr. Carpenter, who has been instructed carefully to examine the books, informs me that during this winter there has been no sign of damp. It is unnecessary for me to allude further to the Ladder Shed, Plank Shed, and Rough Timber Yard (the positions of which are carefully mapped), than to say that the acquisition of this additional ground has given great facility for the orderly arrangement of such offices) imperatively required in an establishment like that of the Royal Observatory.
The Occasional Observatory is erected in the northern part of the South Ground. It is fitted with a stone pier, and in other respects is prepared for reception of the Water Telescope, to which I shall allude hereafter.
For preserving in neatness the footpaths and roads through these grounds, they are protected by low fences of iron wires carried by short stumps.
The Observatory Map has been extended, by the assistance of a professional surveyor, to include the South Ground, and to exhibit the buildings in their present state. Sections of the grounds of the Observatory have also been taken in different directions.
Our galvanic wires are in the same state as at the Visitation of 1869. In the descent of the wires underground from the Observatory, the softened earth above them had yielded to the rain and exposed the iron pipe inclosing the wires; it is covered now by concrete. A general repair of the wires on the poles of the S. E. Railway has been made by C. V. Walker, Esq., Engineer of Telegraphs for the Railway, at the expense of the Observatory, in conformity with the terms of our agreement. On the earth-current wire from Angerstein Wharf to Lady Well, unusual interruptions occurred, the cause of which has never been discovered; they have, however, ceased entirely. The four earth-current wires (two going, two returning) were led from the Magnetic Observatory to a south-west chimney above the dwelling house which communicated with a bed room; the noise made by the wires when stretched tight was so offensive that I have had the attachment shifted to a south-east chimney.
I alluded in the last Report to the difficulty of seeing the Chingford mark in consesequence [consequence] of the growth of the trees of Epping Forest behind it. I have lately learned that those trees are the property of Richard Hodgson, Esq., late Secretary of the Royal Astronomical Society; and I am bound to acknowledge the liberality of that gentleman, in spontaneously undertaking that the trees shall be cleared away whenever it shall be necessary, to the extent that may be required to make the Obelisk visible.
On the state of arrangements regarding a proposed railway through Greenwich town or through Greenwich Park, I am unable to give accurate information. A bill was introduced by the S. E. Railway Company to cancel the proposal sanctioned by Parliament for a line passing through the town and on the north side of the Royal Hospital Schools, and to substitute a line through Greenwich Park. I understand that objection was made to this, and that extension of time was then solicited. The general impression appears to be that the Park is safe from invasion for the present. Meanwhile, it is understood that measures are in progress for forming the short railway from the bottom of Maze Hill in East Greenwich towards Woolwich (making a junction with the North Kent Railway near the Charlton Station) ; a step in every way desirable.
THE Report, now presented to the Board of Visitors, refers to the state of the Royal Observatory on 1871, May 4; giving an account of its general transactions during the interval of twelve and a half lunations, included between 1870, April 30, the date of the last Report, and 1871, May 4. It is divided into the same general heads as in previous years.
I. Buildings and Grounds:–
The changes since the date of the last Report are of no great importance.
In the Astronomical portion of the Observatory some trifling alterations have been made in the roof-shutters of the Transit-Circle-Room.
During the past summer the interior of the Dwelling House has been painted and renovated, many years having elapsed since the execution of any similar works.
The iron door for the Equatoreal Room of the South East Dome, similar to that fitted up for the Chronometer Room, and mentioned in the last Report as in course of preparation, is now mounted in its place, and gives great security against fire in that portion of the buildings.
I have made some preparations for placing sliding doors in front of the Telescope Shed.
In the Magnetic Observatory, the inclosure of the staircase which leads down into the Basement, by pannelled sides and a door in the lower story, has contributed materially in the last year to confine the changes of temperature in the Magnetic Basement within very small limits, by cutting off all currents of air from the external regions.
In May 1870 the Earth-Current self- registering apparatus was removed to the eastern arm of the Basement, where it is nearly in contact with the south wall, being thus more accessible for general purposes; while the removal of the lights to the eastern arm has assisted in correcting the small excess of temperature in the west end of the Basement. At the same time this change has allowed of a convenient arrangement for the automatic impression of hour-lines on the registering barrels.
In the last Report mention was made of the erection of the Occasional Observatory in the South Ground, in preparation for the reception of the Water Telescope. That instrument having been completed, gas-pipes have been laid on, and other arrangements made, to adapt the building to the purpose for which it is now employed.
The paths to and about the Magnetic Ground have been hardened by a covering of tar-paving.
The four earth-current galvanic wires, which were formerly suspended in the open air from a chimney of the Dwelling House to the Electrometer- Mast, are now led (with other wires) in pipes underground from the Battery Basement to the Magnetic Basement.
A Bill has been introduced into Parliament in the present session, in reference to the proposed line of railway through the town of Greenwich. As far as I can gather, the Bill does not propose any change in the line, but merely asks for an extension of time. I imagine, therefore, that it does not affect the interests of the Royal Observatory. In the meantime, workmen are busily employed about a mile east of the town, in completing a line from Charlton Station towards Greenwich, apparently as far as the point at which the sanctioned line through the town and the projected line through the park separate.
The line, promoted some years since by the London, Chatham, and Dover Railway 'Company, was suddenly stopped (in consequence of the financial difficulties of the Company) in an incomplete state, just before reaching the sub-crossing of Blackheath Hill. Workmen are now employed in completing the earthworks and preparing the bridge. The powers of that Company extend to the western wall of Greenwich Park; but it would appear probable that they may endeavour to make a junction (as they originally proposed) with the South-eastern Line.
Experiments made by Mr. Stone, since the last meeting of the Visitors, show clearly that a local elevation, like that of the Royal Observatory on the hill of Greenwich Park, has no tendency to diminish the effect of railway-tremors.
IN accordance with the custom which has now been maintained so many years, and which I believe has received the approval not only of the Board of Visitors but also of the friends of Astronomy in general, I respectfully offer to the Board the following Report. In an Observatory in which the observation of the Moon occupies so much attention, the labours of the establishment are naturally divided by lunations; and for many years past I have therefore determined the epochs of my Reports by the most convenient New Moon or Full Moon. On the present occasion I offer the general history of the Observatory from the Full Moon of 1871, May 4, to the New Moon of 1872, May 7, including a period of twelve and a half lunations; and I report the state of the Observatory on the last-mentioned day. The subdivision of the Report adopted in previous years has been found convenient, and is adopted in the present Report.
I. Buildings and Grounds:–
In the Dwelling-house, the Octagon Room, the North Dome, and the principal range of buildings from the Quadrant Room to the South-east Dome, no alteration has been made which requires the slightest remark.
Two short open-air passages have been roofed with rough glass.
The iron curbs of the South Dome (Altazimuth) and South-east Dome (Great Equatoreal) have been cleansed from rust, and their motion is made much easier than formerly.
The galvanic wires from the Battery Basement under the North Dome to the large clock at the Entrance Gate, which formerly were led round by the iron rails of the Front Court, are now led with many others under the pavement and under the floors of the Observatory Rooms, and are thence carried underground to the clock.
In the Magnetic Observatory, guards have been fixed for the protection of the two telescopes adapted to eye-observation of the horizontal-force and vertical-force magnetometers ; and a shade for protection from the Sun's radiation has been placed on the top of the naphthalizing-house. I am making preparations for fixing platform on the roof of the Magnetic Observatory for the observation of meteors, auroras, &c. The Normal Sidereal Clock, for giving sidereal time by galvanic communication to the Astronomical Observatory, was established in the Magnetic Basement in 1871, June; that locality being adapted for it on account of the uniformity of temperature. Further mention of this clock will occur in a following Section.
On 1871, November 17, the box which carries the insulating glass pillar for the electrometer apparatus, at the top of a pole 80 feet high, was burnt. On the cause of this singular accident I am still in the dark; but it seems possible that, in the gusty weather and irregular burning of the inclosed gas-lamp, soot had been deposited, which had afterwards caught fire from the lamp. The abundant command of water prevented it from doing further mischief. A copper box is now substituted for the wooden box.
The front of the Telescope-Shed on the Magnetic Ground is now completely covered by four large doors. One of these is carried by hinges; the other three slide upon rollers. In this manner one fourth of the length of the shed can be opened at any part.
On 1871, December 1, the Watchman's Clock, upon which are registered the visits of the Night-Watchman, was moved from the Astronomical Observatory to the Magnetic Offices. As the Watchman, while not on beat, occupies the Gate Porter's Cabin, this arrangement insures the visits of the Watchman to every part of our now widely-extended premises. The clock-registers are read and entered in a book every morning.
The South Ground, at the present time, is much occupied with wooden erections in preparation for the observations of the Transit of Venus in 1874. This occupation is only temporary. But the danger of fire would be so great that I have deemed it necessary to establish a third fire-plug in the South Ground (the two others being n the Front Court and the Magnetic Court) in communication with the Water Main, which is always charged with water at about 100 feet pressure.
The aspect of railway enterprise is at present favorable to the Park and the Observatory. The South-Eastern Railway Company has made an arrangement with the Metropolitan Board of Works for shifting the course of the great Southern Outfall Sewer. This enables the Company to trace a new line for the railway, passing on the north side of London Street, with much pecuniary advantage to the Company, and at such a distance from the Observatory as to remove all cause of alarm. I understand that the Bill, which was unopposed, has passed the Committee of the House of Commons. I trust that the contest, which has lasted thirty-seven years, is now terminated; and I shall be happy if it is closed on terms advantageous to the Company, from whom we have received important assistance in the arrangements for time-signals.
A line was contingently proposed for connecting the London, Chatham, and Dover Railway with the new line of the South-Eastern Railway. It has been suspended for the present, but will undoubtedly be taken up again. It will cause no inconvenience to the Observatory.
THE interruption of the use of the Altazimuth for a time has made it less cogent than on other occasions to define the period, to which my Report to the Board of Visitors applies, by New Moon and Full Moon. But, as the termination of the period which is the subject of Report in 1873 becomes the beginning of that which in ordinary course would be included in the Report of 1874, there is still a prospective advantage in retaining the usual principle of limitation; and the Report which I now offer will therefore apply to the interval between New Moon of 1872, May 7, and Full Moon of 1873, May 11.
I. Buildings and Grounds:–
In the buildings which surround the Front Court, the only changes are the insignificant ones, of alteration of the height of the quadrantal steps rising to the Original Entrance, and of erection of small glass roofs outside of the two doors which open into the Observatory Buildings.
The roof-shutter of the South Dome (covering the Altazimuth), of which the ironwork had decayed, was blown off in a heavy gale; but was soon replaced.
The west palings have been extensively repaired. The roof of the carpenters' shed has been raised, to give better fall to the rain-water.
Extensive repairs have been made to our telegraph-wires carried on the poles of the South-Eastern Railway, and new wires have been carried under Deptford Creek. The insulation of the wires appears to be very perfect.
Observations have been made by Mr. Hilgard, principal officer of the American Coast Survey, for determination of a fundamental longitude (as will be further mentioned); and Mr. Hilgard's transit-instrument was planted, for this purpose, in the Magnetic Court. It has been my custom, in similar instances, to fix a stone in the ground, with a short inscription, giving the name of the observer and the instrument which he has used on that spot; and I have followed this custom in the instance of Mr. Hilgard.
The proposed platform above the Magnetic Observatory, to which allusion was made in the last Report, was completed in time for observation of the August shower of meteors in 1872.
In preparation for the proposed photoheliographic observations, a small building with rotatory dome has been erected on the brow of the slope from the Magnetic Ground which overlooks the South Ground, communicating with the Magnetic Office, No. 3; and the office No. 2 is receiving some small alterations to prepare it as Chemical Room.
Provision is made for general external painting of the Observatory Buildings.
The preparations for the Transit of Venus in 1874 still occupy the South Ground. The number of the erections became so considerable, far greater than could with safety or convenience be retained in the South Ground, that I was induced to solicit permission of the First Commissioner of Her Majesty's Works and Parks, for placing many of the buildings, when finished, in the Reserve Ground of Greenwich Park. The First Commissioner's consent was immediately granted, and eight of the buildings have accordingly been transferred to the Park Reserve.
The question of Railway through Greenwich is not yet practically settled. Of the sanctioned line, the eastern portion, from Maze Hill to Charlton, is completed and is opened for daily service. Application has been made to Parliament, and (as I am informed) has been favorably received by the House of Commons, for lengthening the time for completion of the works through Greenwich Town. I could much wish to see the railway actually made.
No further proposal has been made for connexion of this line with the lines of the London, Chatham, and Dover Railway.
THE Report, which I have the honour of laying before the Board of Visitors, refers to the period of twelve and a half lunations included between Full Moon of 1873, May 11, and New Moon of 1874, May 15, and presents the general history of the Royal Observatory during that interval, together with a statement of its condition on the last-mentioned day.
I. Buildings and Grounds:–
The only alteration of any importance in the buildings surrounding the Front Court is the inclosure of the Mean Solar Standard Clock in the Ball Lobby within double sashes, with a view to reducing the alternations of temperature to which this clock is exposed.
A first-floor-room under the Altazimuth Dome, fitted with shelves, formerly called the Upper Depôt, has been taken for extension of the Library, and is called Library 4.
The whole of the exterior of the Observatory Buildings has been painted, under the superintendence of H. M. Office of Works. New gates for the Front Court have been prepared and hung.
A considerable portion of the East Boundary fence has been repaired, and a tool-house has been built in the South Ground.
The platform above the Magnetic Observatory, for observation of meteors, has been used during the past year as a stage for the telescopes employed in the practice. with the Transit of Venus Model, which has been erected on the roof of the Octagon Room. It has been found necessary to strengthen the platform with struts, in order to diminish the tremor experienced in windy weather.
The number of buildings erected in the South Ground, in preparation for the Transit of Venus, has been reduced within reasonable limits by transferring a part of them to a plot of ground belonging to the Admiralty and adjoining the Vicarage, at the north boundary of Greenwich Park. This arrangement has proved more convenient for many of the observers, and has at the same time greatly diminished the risk of fire in the Observatory inclosure. All the huts, except those intended for Egypt, are now taken down and packed for shipment.
A fire-proof chemical room, constructed of zinc, has been erected close to the Photoheliograph, and fitted with a gas-stove for keeping the photographic chemicals at a suitable temperature throughout the winter.
No progress has yet been made in the construction of the Railway through Greenwich; but it is understood that the South-Eastern Railway Company have purchased some property along the line of route sanctioned by Parliament, and which passes on the north side of London Street, at a considerable distance from the Observatory.
THE present Report refers to the condition of the Royal Observatory on 1875, May 20; and gives an account of its general transactions through the period of twelve and a half lunations, included between the New Moon of 1874, May 15, and the Full Moon of 1875, May 20; the arrangement under different heads being n the same as in past years, with the exception of the addition of sections for Photography and Spectroscopy.
I. Buildings and Grounds:–
By occasional repairs, paintings, and small alterations, into which I need not enter, the buildings, &c. have been kept in general good order, and properly adapted to their current wants. The following, however, are more distinct changes.
For viewing the Collimator of the Altazimuth, in a new position, by the telescope of the Altazimuth (as will be hereafter described), the circular wall which supports. the wall-curb of the South Dome has been raised about three inches. No change is made in the exterior wall, except that the perforation is higher than before.
For the service of the Clock Movement of the Great Equatoreal, as will be hereafter explained, a water-cistern has been established in the highest part of the Ball-Turret, and is supplied with water by ordinary ball-service from the Kent Water Works. The height of the cistern from the ground exceeds 40 feet, but the pressure of water in the supply pipes at the ground-level is about 100 feet, and there is, therefore, no difficulty of supply. Care has been taken to increase the protection against frost, and to (rive means of emptying the cistern. As the rising supply-pipe passes close to the door of the Octagon Room, a hose has been laterally attached which can discharge water into the room.
For better examination of the solar photographs introduced in the operations of the Photographic. Department, by light of the sky reflected upwards from a horizontal mirror, a sheet of plate-glass was inserted in one. of the windows of the Lower Computing Room. It soon became evident, however, that greater space was required for that Department, and I have now appropriated to it a room, formerly considered as the room of the Superintendent of the Magnetical and Meteorological Department, but used practically as a place for deposit of the stores of that Department. Perhaps a plate-glass window may be found necessary there.
A water-sink has been established at the head of the stairs to the South-East Dome, close to the door of the observing room of the Great Equatoreal, for use in the photographic employment of that instrument. A small fire-hose is attached to its supply-pipe.
I have inadvertently omitted to state in former Reports that there are on the Observatory Grounds three fire-plugs, always charged with water at a pressure of about 100 feet, and that the Observatory is provided with 220 feet of large fire-hose. The Assistants are periodically exercised in the use of the hose.
The removable buildings, the instruments, and the stores, of the Transit-of-Venus Stations A (Egypt), C (Rodriguez), and D (New Zealand), have now been returned to the Observatory. One Transit-hut (for examination of personal equations) and one Altazimuth-hut (for practice of the officers of the Arctic Expedition) have been again planted in the South Ground. Other of the building-frames and stores are at present lying in the South Ground; and one large collection, by permission of the Department of Works and Parks, is placed in the Reserve Ground of Greenwich Park.
A carefully constructed scale of equal parts, 15 feet in length, employed by Mr. De La Rue in Kew Park, for examination of photographic distortion, and lent by him for present use at the Royal Observatory, has been suspended at the north-east angle of the Octagon Room. The photographic hut of Station A has been placed, by permission of the Superintendent of the Royal Naval School, in the grounds of that school for photographic examination of the scale.
Two piers have been built in the South Ground for mounting two transit instruments belonging to the Admiralty, for practice of the Officers of the Arctic Expedition.
For many years past, reports on the progress of the proposed Railway through Greenwich have been matters of great interest to the Board. At present I have merely to state that the works of the railway have really advanced from the east through the northern grounds of the Naval School, at a distance from the Observatory which leaves no fear of sensible tremor; and mention of it may well be omitted from all future reports.
THE Report which I now present is intended to exhibit the condition of the Royal Observatory on 1876, May 8; and to give its general history through twelve lunations, beginning with the Full Moon of 1875, May 20. The Report is closed at a somewhat earlier period than usual, as the number of subjects on which information is to be given has increased in the later years, and the leisure for writing is at the same time diminished.
I. Buildings and Grounds:–
I have often been struck with the exposed position of the Observatory, as regards the liability to burglary and theft; and have determined to make one place secure, in which, if necessary, valuable objects might be deposited. The small Manuscript Room, a separated portion of the Old Quadrant Room, having brick roof and iron door, required nothing but a proper lock on the door and iron bars on the window; these have been lately applied.
At the door from the front court to the staircase of the Octagon Room (the original entrance to the Observatory as erected by Sir Christopher Wren), a small porch shelter has been often desired. I propose to fix there a fan-roof of quadrantal form, covering the upper flat stone of the external steps. I scarcely need to say that I shall be careful to avoid interference with the venerable Tablet, whose noble and simple enunciation of the purposes of the Observatory has, I am persuaded, been most beneficial to its constant conduct.
The visitors will have remarked a wooden stage fixed upon the top of the Quadrant Room, for giving access to the light which illuminates the Collimating mark of the Altazimuth. Though necessary when the galvanic apparatus failed, it is now little used, the action of the galvanic induced current being uniformly successful.
In the Battery Basement, inconvenience arose and insulation was sometimes endangered by the position of the cells of galvanic batteries upon wooden shelves. They are now all placed upon shelves of rough glass.
A small water-hose is established in the Magnetic Observatory.
Of the various portable buildings for the observation of the Transit of Venus, some are left in their lonely positions for the use of voyagers who may accidentally visit those localities; some are deposited at Simons Town, and I am encouraged by the Hydrographer to hope that they will be returned in the current summer; those which have been brought to Greenwich have undergone numerous shifts. At present, one hut is at Chatham, and four at the Exhibition at South Kensington; others are on our grounds, or in the Reserved Ground of Greenwich Park.
Mr. De La Rue's scale of equal parts was suspended at the date of the last Report, in a vertical position. On taking photographs of it, by use of a photoheliograph planted in the grounds of the Royal Naval School, we found that the horizontal edges of the photographs of the plates were always indistinct, as if the building trembled vertically, or as if there was vertical irregularity of atmospheric refraction. On placing the scale upon the top of the Octagon Room in a horizontal position, the vertical edges (the only ones with which we had now to treat) were quite sharp, and we have had no farther trouble. We may now contemplate its early removal.
In the Magnetic Basement it has been found necessary to extend, in the westerly direction, the bearing surface of the pier which supports one foot of the stand of the upper declination-magnet (as will be mentioned hereafter). This is done by placing a stout plank of slate upon the brick pier, one end of it projecting sufficiently beyond the edge of the pier, the other end being held downwards by a brass cramp whose lower end is fixed to the pier.
THE Report now presented gives the general history of the Royal Observatory through the period of twelve and a half lunations, comprised between 1876, May 8, and 1877, May 13, and exhibits its condition on the last-mentioned day. No alteration has been made in the arrangement of the heads into which it has, for years past, been found convenient to divide the Report.
I. Buildings and Grounds:–
The fan-roof alluded to in the last Report has been fixed at the entrance to the staircase of the Octagon Room.
In the Transit-Circle Room an alteration has been made in the pitch of the roof-shutters, the fall for water having been found insufficient. The interior of the room has recently been re-painted.
Much inconvenience from wet has been long experienced in the South-East Dome, notwithstanding the care that has always been taken to keep the roof in proper repair. Gutters have now been fixed on the vertical shutter and under the long hinge of the horizontal shutter, to prevent any dripping of water on the instrument.
The wooden stage for giving access to the light of the Altazimuth Collimating Mark has been used more frequently than in the preceding year. A thorough revision of the galvanic apparatus appears to be necessary.
The scale of equal parts, 16 feet in length, lent by Mr. De La Rue for determination of the distortion of the Photoheliographs of the Transit of Venus, has been taken down from the roof of the Octagon Room, and is now deposited in the Great Shed.
The portable buildings for the Transit of Venus, which at the date of the last Report were left at Simons Town, have been returned to England; but it has not been thought necessary to preserve their flat walls; the roofs and the mechanism have been separated, and are lodged in the Reserved Ground of the Park. I propose to submit to the Lords Commissioners of the Admiralty a request that one of the Transit Huts (now at the South Kensington Museum) be lent to Mr. David Gill, for use in his intended heliometer-observations of Mars at the approaching opposition of that planet, referring to the determination of Solar Parallax.
The buildings and fences are maintained in general good order. Some brick piers which have been used in various astronomical operations are left standing (for the present) upon the grounds. In particular, the two piers used by the Austrian observers of longitude to carry their two forms of transit-instrument are left in place; when it becomes necessary to remove them, their places will be marked (as in preceding instances) by flag-stones with appropriate inscriptions.
The railway through the town of Greenwich is not yet opened for thorough traffic.
SINCE the date of my last Report to the Board of Visitors, 1877, May 13, the lapse of twelve lunations leads to 1878, May 2. I am induced by this circumstance to close the present Report on May 2, describing the state of the Observatory for that day, and adverting to the transactions which have occurred between the two Reports. The different subjects are treated in the usual order.
I. Buildings and Grounds:–
I have rarely had so little to report under this head as on the present occasion.
Of the portable huts used for the Transit of Venus: two Photoheliograph Huts are at the Cape of Good Hope and at South Kensington; and one Transit Hut, conveyed to Ascension for the use of Mr. Gill in observations of Mars for solar parallax, has been left there for the use of the Military Establishment. All others are either lodged in the Reserve Ground of Greenwich Park, or are abandoned or broken up.
The buildings, &c. are in general good order.
A small alteration has been 'made in the windows of the Dip Observatory; not for facilitating the dip-observations (which rely on gas-light) but for convenience of illumination on papers, &c.
I continue to remark the approaching necessity for Library extension. Without having absolutely decided on a site, I may suggest that I should wish to erect a brick building, about 50 feet by 20, consisting of two very low stories (or rather of one story with a gallery running round its walls), so low that books can be moved by hand without necessity for a ladder. The site which appears most convenient is that at present occupied by the rubbish-yards of workmen, facing the eastern window of the Magnetic Observatory; care, however, must be taken in the selection of materials. For convenience of access to such a site, as well as to the Magnetic Observatory and other buildings, a light roof over the Magnetic Passage would be very desirable.
The railway through the town of Greenwich has been opened some months. No effect of its proximity (the distance is about 1700 feet) has been discovered at the Observatory.
THE present Report refers to the period of thirteen lunations from the New Moon of 1878, May 2, to the New Moon of 1879, May 20, and presents the condition of the Observatory on the last-named day. The Report is arranged under the usual heads.
I. Buildings and Grounds:–
In the Octagon Room some troublesome repairs have been required. It was discovered that dry rot had attacked extensively the wood-work in the neighbourhood of the north window, and the whole of the wainscoting in this part has therefore been restored. At the same time it was found necessary to renew a beam which supported the brick-work over the window. The whole is now in a sound state.
The ceiling of the Octagon Room has been whitewashed (the first time since 1854). The walls will probably require painting before long.
Preparations have been made for the erection of the new Library near the Magnetic House. A sum has been placed on the estimates, and the general plan has been arranged with the Works Department of the Admiralty. The clearing of the ground is advancing.
THE dates of the Annual Reports have usually been made to depend on the limits, or on the middles, of lunations. On the present occasion the New Moon of 1880, May 9, appeared to be the most convenient day; and the entire period of the Report, extending from the New Moon of 1879, May 20, to that of 1880, May 9, is somewhat shorter than has been usual.
I. Buildings and Grounds:–
The Visitors will have remarked, in the upper part of the wall which divides the Front Court from the North Terrace, a circular hole. This has been made in order to allow a clear view from the Altazimuth of a mark which I have been permitted, by the courtesy of the Governor of the Royal Naval College, to fix upon the parapet of the south-east building of the College. I shall again advert to the object of this mark.
Since the serious attack of dry rot in the Octagon Room, which was met, and I trust conquered, as described in the last Report, there has been no further appearance of that dangerous invasion. But a leak in the leadwork (Sir Christopher Wren's, I believe,) above the south window of the same room caused some alarm. After repair of the leak I have taken down the upper woodwork of the window, and I propose to keep the pannel open for drying and ventilation until I can be confident that there is no fear of appearance of fungus.
I stated in the last Report that steps had been taken for the erection of a new Library near the Magnetic Observatory. The Admiralty, on final consideration of the estimates, decided not to proceed with the work; and they have repeated that decision in the present year. In the meantime the space has been cleared (which, in consequence of the necessity of removing some offices, was a more troublesome work than was anticipated), and I am confident that the Visitors will recognize that the state and general appearance of the Observatory Grounds are much improved. The space will admit of the erection of a building 50 by 20 feet; and I propose to erect here a room of one story, but with galleries at mid-height, so that there would never be need to use a ladder. Among other changes occurring in this clearance, I have removed the Electrometer Mast (a source of some expense and some danger); the perfect success of Sir William Thomson's Electrometer rendering all further apparatus for the same purpose unnecessary: and have changed the position of the well and pump used for draining the Magnetic Basement. The demand for additional library-room becomes more and more pressing.
The subterranean telegraph-wires through the Park, connecting the Royal Observatory with the wires of the South-Eastern Railway, have lately become partially inefficient. The authorities of the General Post Office have been engaged in restoration of the wires; and, in furtherance of the same object, they are considering the adoption of a new line through the streets of Greenwich.
The present Report refers to the period of twelve and a half lunations between the New Moon of 1880, May 9, and the Full Moon of 1881, May 13, and exhibits the state of the Observatory on 1881, May 13.
I. Buildings and Grounds:–
The erection of the proposed new Library, the site for which had been cleared last year, has been sanctioned by the Government, and the work will be carried out under the superintendence of the Director of Works to the Admiralty. The building is to consist of a room of one storey, 50 by 18 feet, with galleries at mid-height. To make room for the new Library, the fire-hydrant near the Magnetic Observatory has been moved a short distance. (It may here be mentioned that the fire-hose is periodically tested, and all the members of the staff are practised in its use.)
Some trouble has been occasioned by the intrusion of water into the Magnetic Basement, the source of which has not been perfectly traced.
Halley's ancient tombstone, after its removal from Lee Churchyard (where it has been replaced by a new stone with a fac-simile of the inscription), had been placed in the South Ground, where it has been lying for several years. It has now been carefully restored, and mounted on the east wall of the lobby of the North Dome.
The new line of underground telegraph-wires has been completed by the officers of the General Post Office. The new route is down Croom's Hill, joining the ordinary Post Office wires at the corner of London Street, instead of through the Circus and Circus Street as heretofore. The result of this change, at least as regards the earth-current-wires, and probably as regards the other wires, has not been satisfactory. Allusion will be made, in a following section, to the difficulties which have been introduced. The telegraphic authorities of the General Post Office have been engaged in the search for the causes of the abnormal indications, but have hitherto found no fault in the wires. I am proceeding to change the earth-plates.
The Report here presented refers to the period of twelve months ending 1882 May 20, a fixed date being taken, conveniently near to the Visitation Day. Sir G. B. Airy resigned his office on 1881 August 15, and a portion of the observations here referred to were made under his superintendence. There seems to be no occasion to separate these from the remainder, as the course of observation which Sir G. B. Airy has carried out for so many years has been continued without essential alteration in its main features.
I. Buildings and Grounds, Moveable Property, and Library:–
The new Library, a building 55 feet long and 18 feet broad, was erected at the end of last year, but the walls were so damp that the whitewashing of the ceiling had to be deferred till the middle of May, and it is only now ready for the reception of books. It is proposed to transfer to the new building, which is close to the Magnetic Observatory, the sections Magnetism and Meteorology, as well as books in other sections, and manuscripts from the Record room, to which reference is seldom made. Sufficient space will thus be gained for the proper arrangement of books in the two rooms forming the old library, which is more conveniently placed for the use of the Astronomical Department. The usual annual comparison of books and manuscripts with the catalogue has been made. The missing manuscript book of Altazimuth Zenith Points has at length been found at the binder's, where it had been mislaid.
The rooms of the Magnetic Observatory have been whitewashed, and some repairs to the buildings generally have been carried out preparatory to the outside painting.
A subsidence of the ground having taken place last summer in the garden south of the transit-circle, close to one of the supposed sites of the well dug by Flamsteed for observation of stars in the daytime, an excavation was made, but no traces of the well could be discovered.
The period to which the present Report refers comprises the twelve months ending 1883 May 20.
I. Buildings and Grounds, Moveable Property, and Library:–
The presentation of the Lassell two-feet reflecting telescope by the Misses Lassell, of which further mention will be made, has necessitated some alterations in the buildings and grounds. It has been mounted in the South Ground, and a circular building 30 feet in diameter has been erected in preparation for the dome. The dip and deflexion instruments have in consequence been moved from Magnetic Office No. 7 to the New Library.
The exterior of the Observatory Buildings and the interior of the Octagon Room have been painted under the supervision of the Director of Works of the Admiralty, to whom the charge of maintenance and repairs of the buildings has been transferred.
Under a new arrangement, several articles of office furniture have been supplied by the Director of Stores' Department.
The present Report refers to the period of twelve months from 18S3 May 21 to 1884 May 20, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The new dome for the Lassell telescope was completed by Messrs. T. Cooke and Sons at the end of last March, and is in every respect satisfactory. It is 30 feet in diameter, covered with papier mâché on an iron framework, and turns with great ease. The shutter-opening extends from beyond the zenith to the horizon, and is closed by a single curved shutter (3 ft. 6 in. wide at the zenith and 6 feet wide at the horizon), which turns about a point in the dome-curb opposite to the shutter-opening, and runs on guiding rails at the horizon and near the zenith, the curved shutter being continued by an open framework to complete the semi-circle. This arrangement appears to leave nothing to be desired as regards ease of manipulation. After the completion of the dome, the carpenters' work on the flooring, &c. of the building and the attachment of the observing stage (which is fixed to the dome) have necessarily occupied much time, and the building is hardly yet complete in all details.
Under the supervision of the Director of Works f the Admiralty, extensive improvements have been made in the arrangements for the drainage of the Observatory, and preparations have been made for connecting it with the Main Drainage System. Several rooms in the Observatory Buildings have been painted during the past year.
THE Report here presented refers to the period of twelve months from 1884 May 21 to 1585 May 20, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The new building and dome for the Lassell telescope were completed in all details during the past year. A stove has been fixed in it to dry the interior in wet weather, as it was found that the mirror and ironwork of the instrument were exposed to injury from damp.
The work of connecting the drainage of the Observatory with the Main Drainage System has now been completed by the Director of Works' Department. It is intended to lay a drain to carry away the waste water from the sink in the Magnet basement, and I propose to take advantage of the opening of the ground to lay a line of pipes underground for the ventilation of the basement by air which has acquired the temperature of the soil at a depth of several feet below the surface. It is hoped that by this means greater uniformity of temperature may be maintained in the Magnet basement.
A shed for the new photographic, thermometers has been erected in the south ground.
The Observatory fences have been thoroughly repaired, and are now in good order.
THE Report here presented refers to the period of twelve months from 1885 May 21 to 1886 May 20, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
As proposed in the last Report a line of 9-inch pipes about 155 feet in length has been laid underground for the ventilation of the Magnet basement, the depth below the surface varying from 5 feet at the lower end in the South Ground to 11 feet 6 inches at the entrance to the basement. Thus the air which is admitted (by means of two branch pipes) into the east and west arms of the basement is -warmed in winter and cooled in summer by passage through a considerable extent of soil at nearly constant temperature. A drain for carrying away the waste water used in the photographic operations is laid below the line of ventilating pipes, the latter being carefully isolated from the drain pipes.
Much inconvenience has been felt from the small size of the two Computing Rooms, and though this has been partially met by removing the Spectroscopic and Photographic branch to the New Library, the air-space still seems insufficient, whilst the removal of a part of the establishment to a distant building is not altogether satisfactory. The lower Computing Room could be considerably enlarged by including the Quadrant Passage, and the area of the Upper Computing Room could be more than doubled by extending it over the ancient Quadrant Room.
The Transit-Circle Room and the passages in the East Buildings have been painted.
Communication by telephone has been established between the Astronomer Royal's Office and the Magnetic Observatory, a pair of telephones with battery having been supplied by the Post Office for the purpose. A speaking tube has been fixed for communication between the Upper and Lower Computing Rooms.
A portable electric lamp has been purchased for use in examining the interior of clocks and in spectroscopic observations.
A transit hut with canvas roof was erected in the South Ground last summer for the use of Commander Moore and Lieut. Douglas of the Royal Navy, and remains available for any occasional transit observations.
The present Report refers to the period of twelve months from 1886 May 21, to 1887 May 20, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The extension of the two Computing Rooms, to which reference was made in the last Report, has been sanctioned by the Admiralty, and provision for the work has been made in the estimates. Detailed plans have been prepared in which it is arranged that the Quadrant Passage should be included in the Lower Computing Room, and that the Upper Computing Room should extend over the Safe Room, with a central opening and spiral staircase to establish ready communication between the two rooms. Above the extended portion of the Upper Computing Room, a dome 18 feet in diameter is to be erected, in which it is proposed to mount the Cooke 6-inch equatoreal, the photoheliograph tube being attached to the same mounting. The combined instrument will be carried on a pier to be built on the top of the old Quadrant Pier, which appears to he sufficiently firm for the purpose, and will command complete view of the Sun throughout the day – an important consideration, as the work of the photoheliograph in its present position is seriously interfered with by trees and the Lassell dome. The 6-inch Cooke refractor will he available for occultations, phenomena of Jupiter's satellites, and other occasional observations. It may be anticipated that the concentration of the astronomical establishment thus effected will prove of great advantage.
Arrangements have been made for warming he South-east dome in damp weather by means of heated air passing through a large grating under the instrument from the stove in the Chronometer Room, which has been shifted to a suitable position.
A photographic dark room has been fitted up on the staircase-landing of the South-east dome.
A lathe, with a set of chucks and turning tools, has been procured and set up in the basement of the Lassell building.
Four portable pneumatic fire-engines have been supplied to the Observatory by direction of the Admiralty.
The Report here presented refers to the period of 356 days from 1887 May 21, to 1888 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The building operations for extension of the Computing Rooms and erection of a dome 18 feet in diameter were commenced on November 7 and completed by April 21, with the exception of the new dome made by Sir Howard Grubb, which is now nearly finished. The Assistants and Computers of the Astronomical Branch were, in the meantime, transferred to the Octagon Room, where temporary arrangements had been made for carrying on the office work. New desks and shelves for books have been fitted up in the Computing Rooms and sinks for photography have been -fixed in the Dome Room, the north portion of which is to be partitioned off as a photographic dark room. A fire-place with provision for ventilation has also been fixed in the Astronomer Royal's Official Room. The increased space available in the new rooms and the ready means of communication between the upper and lower rooms are felt as a great convenience, and as the Spectroscopic and Photographic Branch has been transferred to the Upper Computing Room, the whole of the astronomical establishment is now brought together. It is intended to mount the Cooke 6-inch equatoreal, with the photoheliograph tube attached, on the new pier as soon as the 18 -foot dome is completed.
The alterations required in the Safe Room in connexion with the work on the new rooms and pier necessitated the removal of Bradley's North Quadrant, which has been placed in the Transit-Circle Room. The South Quadrant which is mounted on the east face of the pier has not been disturbed.
A new flue with independent outlet has been fitted to the chronometer oven to carry off the fumes from the gas jets. The South-east dome has been warmed during the winter months by means of heated air from the stove in the Chronometer Room, as explained in the last Report.
The Cooke 6-inch equatoreal has been mounted temporarily in the South Ground since the beginning of last June for observation of occasional phenomena, a portable transit hut, with canvas flap on its roof, being used to protect it from the weather.
The subject of approaching railways has again, after a lapse of many years, engaged our serious attention. Early in March notice was received from the Home Office of a proposal to carry a railway (in extension of the authorized Bexley Heath Railway) in a tunnel across Blackheath, the nearest point being 840 yards from the Observatory. As there was reason to believe that this railway might injuriously affect the Observatory, preliminary observations of the effect produced by trains on the existing Greenwich-Maze Hill Railway were at once commenced, the observations being made on six nights with the transit-circle and the disturbance in the image of the wires, as seen by reflexion from the trough of mercury, being noted. It resulted from these experiments that trains on this railway caused great disturbance during their passage, not only on the section between Greenwich and Maze Hill, the nearest point of which is 570 yards from the transit-circle, but also on the line beyond Greenwich on the London side and beyond Maze Hill on the Woolwich side. The distances of the Greenwich and Maze Hill stations from the Observatory are about 970 and 670 yard respectively. There was also evidence of disturbance caused presumably by trains on the Lewisham, Blackheath and Charlton line at a distance of about a mile from the Observatory, but we could only infer the times of passage of these trains from the published time-tables.
In order to establish conclusively the connection between definite disturbances and trains, arrangements were made to note the times of arrival and departure of trains on the Greenwich line and at Blackheath, facilities for doing this having been courteously given by Mr. Myles Fenton, the Manager of the South-Eastern Railway. Observations were made on this plan on five nights, one observer being stationed at the transit-circle to record all disturbances of the reflected image, while another observer travelling up and down the Greenwich line, and a third observer at Blackheath noted the times of arrival at and departure from the stations. It was found that the disturbance was very great during the passage of trains between Greenwich and Maze Hill, the reflected image being invisible while the train was in the tunnel, at a minimum distance of 570 yards, and that there was considerable disturbance during the passage of trains through the Blackheath-Charlton tunnel, at a distance of a mile, the reflected image becoming occasionally invisible. As the tunnel of the proposed railway would be similar in character to this, but at half the distance, it was concluded that it would cause so great a disturbance as to make delicate observations impossible. On my notifying this to the Admiralty, the bill was opposed on the part of the Government, and as a consequence of this the clauses authorizing the construction of the railway across Blackheath were abandoned.
I may here mention that the extension of the London, Chatham, and Dover Railway from Blackheath Hill to Greenwich, which was authorized in 1881, is now in course of construction. I hope that, though the terminus of this line is distant only 620 yards from the Observatory, the tremor from trains will not have sufficient time to produce the full accumulated effect in the short interval between Blackheath Hill station and the terminus. But if at any future time a further extension of this line should be proposed, the question would require very careful consideration in the interests of the Royal Observatory.
The Report here presented refers to the year from 1888 May 11 to 1889 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The new 18-foot dome, constructed by Sir Howard Grubb over the enlarged Computing Rooms, was completed shortly after the date of the last Report, and the north portion and corners of the room have been partitioned off to form photographic dark rooms and a staircase lobby, in preparation for work with the 13-inch Photographic Equatorial which is to be erected there in the course of this year.
The exterior of the Observatory buildings and the. interior of the Astronomer Royal's Office, and of the Computing Rooms, have been painted in the course of the year.
Two copper Lux Calor gas stoves have been fixed at the east and west ends of the Magnet basement to raise the temperature of the horizontal and vertical force magnets in winter to equality with the summer temperature. A Lux Calor iron stove has also been fitted in the new portion of the Upper Computing Room.
The Admiralty have sanctioned the building of a suitable Lodge for the gate-porter in place of the small wooden hut which has been used for that purpose for many years.
Bradley's North Quadrant (removed from the Safe Room last year) has been mounted on the west wall of the Transit-Circle Room.
Owing to want of Space in the Observatory buildings the moveable instruments, clocks, and other apparatus which are not in actual use, are for the most part stowed away in their boxes in wooden sheds, where their periodical examination and renovation are attended with great difficulty. For the proper care of these instruments it would be advisable that they should be housed in a brick building to serve as an Observatory museum for instruments and apparatus of scientific value or historical interest. A building of one story, about 40 feet long and 30 feet broad, would be suitable for this purpose, and a convenient site would be in the South Ground, the proposed building being connected with the circular Lassell building. In that situation it would not interfere with the use of the astronomical or magnetic instruments, a consideration of much importance.
The Report here presented refers to the year from 1889 May 11 to 1890 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The fittings of the photographic dark- rooms in the new 18-foot dome have been completed, and all preparations made for work with the 13-inch Photographic Equatorial recently mounted there.
The Ball-Lobby and the staircase leading to the Octagon Room have been painted; and also the room assigned as a private room to the Computers.
The building of the new Porter's Lodge, which was sanctioned last year, has been somewhat delayed from various causes. The contract for its construction has just been signed, and the work will begin immediately after the Visitation.
The Admiralty have authorized the building of a storehouse or museum for the better housing of the various portable instruments and apparatus belonging to the Observatory, as proposed in the last Report. After careful consideration, it appeared advisable to modify the original idea of a building of one storey occupying nearly the whole of the ground available for future extensions, and to arrange for a building of two storeys having a smaller area, designed to form the eastern wino, of a larger structure, with the Lassell Dome as the central portion. The other wing would provide a suitable Computing Room for the Magnetic and Meteorological Branch, and sleeping accommodation for observers charged with observations in the early morning. The Ante-room of the Magnetic Observatory, which now serves as the Computing- Room for that branch, is hardly fit for the purpose, as it is built of wood, and is not large enough for the proper accommodation of seven persons. The effective use of the Lassell telescope for the observation of occultations and phenomena would be greatly increased if it were mounted at a greater height, as it would be if the plan here suggested were carried out. In its present position neighbouring trees interfere greatly with the observations of the Moon and Jupiter when south of the equator, and the use of the instrument is much restricted in consequence.
The Report here presented refers to the year from 1890 May 11 to 1891 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The new Porter's Lodge, mentioned in last year's Report, was completed last autumn.
After much consideration it has been decided that the Museum or Storehouse for portable instruments and apparatus should be built so as to form the central octagon of a future cruciform structure in the South ground, which would accommodate the Physical Branch of the Observatory, and would carry the Lassell Equatorial and Dome at such a height above the ground that the neighbouring trees would not interfere with the effective use of the instrument. The building for the Museum (consisting of the two lower storeys of the octagon) was commenced at the beginning of March and is now nearly completed so far as the structure is concerned. In consequence of a recent decision of the Admiralty to largely increase the number of chronometers and deck watches for the Navy, additional accommodation for chronometers is required immediately, the space in the present Chronometer Room being insufficient even for existing requirements. A proposal is now under the consideration of the Admiralty to provide this by appropriating the room under the Chronometer Room and the Lower Record Room to chronometers, the South wing of the proposed Physical Observatory being built to receive the contents of these two rooms.
In other directions the difficulty of providing in the existing Observatory buildings for the accommodation of the increasing staff and of the accumulating material is severely felt, and it is very desirable that the pressure on the space available should now be relieved by means of a comprehensive scheme, which would supply a suitable fireproof brick building to replace the wooden sheds and huts which now disfigure the Observatory grounds, and to provide for the expansion which has taken place in late years and which may be expected to continue in the future. Amongst the requirements which are now pressing and for which provision would be made in the proposed building may be mentioned:–
(1) A computing; room for the Magnetical and Meteorological Branch in lieu of the small Ante-room of- the Magnetic Observatory which is built of wood and unsuited to present requirements.
(2) A computing room for the new Astro-photographic Branch.
(3) Fireproof rooms for the photographic records and books of calculations in these two branches.
(4) A library for the Physical Branch (Magnetical and Meteorological, Spectroscopic and Photographic).
(5) A store room for the stock of publications of the Observatory, at present housed in a wooden shed where they suffer much from damp.
(6) A laboratory and dark galleries for spectroscopy and photography.
(7) Bedrooms for occasional use by the observers.
An essential part of the scheme would be the mounting of the Lassell Equatorial, with the 12¾ -inch refractor substituted for the Lassell reflector, on the central octagon (above the spectroscopic and photographic laboratory) in a position in which it could be used with great advantage for equatorial observations of various kinds.
A permanent Transit Pavilion has been erected in the Front Court (in the line of Bradley's meridian) in place of the wooden hut set up in 1888 for the Paris Greenwich longitude operations, as experience has shown that this is a very convenient site for longitude determinations and for the instruction of Officers and others in transit observing. It was hoped that the building would have been ready for the determination of the longitude of Montreal this summer, but the work was not commenced till the beginning of March and there has been further delay in the construction of the roof, which consists of a pair of semi-domes sliding apart so as to give a clear opening of 2 ft. 6 ins. These were specially designed in the Department of the Director of Works to the Admiralty to satisfy the astronomical conditions and avoid abnormal refraction at any part of the opening.
To provide for the efficient working of the 28-inch refractor about to be mounted on the South-east Equatorial, the Admiralty have authorized the construction of a new iron-framed dome, 36 feet in diameter, to be erected on the South-east tower in place of the existing wooden drum, which, as mentioned in the last Report, has been so much strained in the course of thirty years, that there is great difficulty in tanning it. An attempt was made to render the existing dome more serviceable by bolting the framework together more thoroughly and by substituting properly turned spheres for the cannon balls, but though the dome is not now liable to stick fast as formerly, it is still very difficult to turn, and cannot be considered serviceable. The new 36-foot dome which is being constructed by Messrs. T. Cooke & Sons is of peculiar form, adapted to the conditions of the case, the diameter being greater than that of the tower on which it is erected. A general description of its special features is given in the Monthly Notices R.A.S. for 1891 May.
The shelves in the Battery Basement have been renewed, teak being substituted for deal.
I cannot present my usual Report without a reference to the loss we have sustained by the death of Sir G. B. Airy, who for 60 years has been connected with the Royal Observatory as Astronomer Royal, or a, Member of the Board of Visitors. The annual Reports to the Board of Visitors which he originated and which, as Astronomer Royal, he presented during 46 years remain as a lasting record of his able and devoted conduct of the work of the Observatory. The personal attachment to the Royal Observatory which characterized his life has been fittingly shown on his death by a bequest of his books and manuscripts, which, valuable as it is, will be valued all the more for the spirit which prompted it.
The Report here presented refers to the year from 1891 May 11 to 1892 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds. Moveable Property, and Library:–
The Admiralty have authorized the building of the South wing of the proposed Physical Observatory during the present financial year, in order to provide additional accommodation for chronometers and deck watches, the room under the Chronometer Room and the Lower Record Room to he appropriated to chronometers as soon as the South wing is ready to receive the contents of these two rooms. The completion of the proposed Physical observatory by the building of the three other wings and of the two upper storeys of the central tower (to carry the Lassell Equatorial and Dome) has been postponed for the present, the admiralty, while recognizing the desirability of carrying out the work, being unable to make provision for it in the current financial Sear. The objects for which the new building is required were set forth in my last Report, and the experience of the past year has shown the urgent need for the accommodation which would be provided by the proposed Physical Observatory.
The new 36-foot dome to be erected on the South-East tower for the accommodation of the new 28-inch refractor is not yet completed, great delay having occurred in its construction by Messrs. T. Cooke & Sons, partly occasioned by the necessity for the erection of a larger workshop before it could be commenced, and partly by the nature of the work.
The pair of semi-domes for the new Transit Pavilion in the Front Court was completed last October, and the building is now quite satisfactory. Before the completion of the roof, the portable transit, used in this building while the transit-circle object glass was being repolished, was protected by a canvas tent.
The Report here presented refers to the year from 1892 May 11 to 1893 May 10, and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Moveable Property, and Library:–
The building of the South wing of the proposed Physical Observatory, in order to provide additional accommodation for chronometers and deck watches, was commenced on November 24 last, but was interrupted on March 4, on arriving at the first floor, by a failure in the supply of terra cotta. Building operations are now about to be re-commenced. The need for further accommodation is being more urgently felt every day, in all departments of the Observatory. A number of the staff are at present housed in the Octagon room, which is part of my official residence; and the inconvenience of this arrangement was strikingly demonstrated during the last winter. In view of this the Admiralty have now authorized the building of the North wing of the Physical Observatory and the completion of the central octagon by the addition of a storey and the erection of the Lassell Dome over it, a much needed extension, the postponement of which, since it was first brought forward in 1891, has caused serious difficulty in carrying on the work of the Observatory, both as regards observations and computations.
The new Museum building, forming the central portion of the Physical Observatory, has at length been fitted with the necessary glass cases, which are now, nearly ready for the reception of portable instruments and apparatus.
In the New Library four cases of shelves have been fitted on the west side of the gallery for the storage of forms, of which a large stock is required for entry and reduction of the observations and for other purposes. Two large cases are also being fitted, one to hold 10-inch solar photographs, the stock of which has already filled one case, and the other the 16-centimetre stellar photographs for the Astrographic chart, which are rapidly accumulating.
In preparation for the erection of the new 36-foot dome on the South-East tower, the old cylindrical dome was dismounted in November last, and the mounting of the new dome was commenced on December 16 and completed on April 25. The work of construction and erection of this large dome has been completed most satisfactorily by Messrs. T. Cooke & Sons, who have skilfully overcome various difficulties encountered in carrying out a novel design.
The usual external painting of the Observatory buildings and domes was done last autumn, with the exception of the South-East dome and building, which are now being- painted.
An inventory of moveable property has been completed as far as circumstances would allow, a portion of the old instruments and apparatus being stored in sheds, where they are not at present accessible for examination. This inventory will require thorough revision when the completion of the new Physical Observatory allows of a rearrangement on a more permanent basis, and, in the meanwhile, considerable changes in the storage of the moveable property will-result from the utilization of the new glass cases in the Museum building.
The Report here presented refers to the year from 1893 May 11 to 1894 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Moveable Property, and Library:–
The South wing of the Physical Observatory, intended to relieve the pressure in the Chronometer room, was at length completed after many delays on April 20, and is now being prepared for occupation. The building of the North wing and completion of the central octagon by the addition of a storey and the erection of the 30-feet Lassell Dome over it, which was authorized more than a year ago, has not yet been commenced, but it is understood that tenders for the work have been invited, and it is hoped that there -w-ill not be much further delay in providing this much needed extension. The details of this building have required careful consideration, and the plans have been skilfully worked out by Mr. Crisp under the supervision of the Director of Works for the Navy to meet the special requirements.
The Photoheliograph hut and instrument were temporarily mounted on the concrete terrace roof of the South wing for daily observation of the Sun on April 26, the rotatory, roof of the hut having been altered to make it portable.
The generating plant for the electric light installation, supplied by Messrs. Johnson and Phillips, was set up and brought into successful action at the end of March, as soon as the progress of work on the new building would allow. The gas engine and dynamo are placed in the ground floor of the new South wing of the Physical Observatory, the accumulators in the adjoining shed, and a Brooke’s electric main is laid from the South wing to the Transit Circle lobby, from which distributing leads can readily be carried to the principal instruments and office rooms. This has, however, not yet been arranged, and the use of the electric light plant is at present confined to charging portable accumulators for use with some of the instruments.
New gas and water mains have been laid to the Physical Observatory, with a separate service to the gas engine.
The plans of the building for the new Universal Transit Circle or Altazimuth have been prepared under the supervision of the Director of Works, and it is hoped that the work will be commenced very shortly. Great pains have been taken by Mr. Crisp in designing this building to adapt it to the somewhat peculiar conditions with a due regard to architectural appearance, and the result appears to be in every way satisfactory.
A permanent timber stage with sliding platform has been put up on the South side of the Great Equatorial to give access to the 28-inch object-glass, and has been found very useful.
The Post Office authorities have courteously arranged to place a wall letter-box for the convenience of the Observatory in the boundary wall near the entrance.
The Report here presented refers to the year from 1894 May 11 to 1895 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Moveable Property, and Library:–
The South wing of the Physical Observatory, which, as mentioned in the last Report, was completed on 1894 April 20, has been utilized to provide indirectly additional accommodation for chronometers and deck watches, and to relieve the pressure in the Computing Rooms. The ground floor has been fitted up as the Mechanics’ workshop, the gas engine and dynamo for electric lighting being placed there, and the room under the Chronometer Room which is thus set free has been fitted up for chronometers. The principal room and the attic are used provisionally for the accommodation of a portion of the staff, the former for the Heliographic and Altazimuth Branches and the latter for the Astrographic Branch. Dark rooms for photography have been fitted up provisionally in the lobbies on these two floors.
The building of the North wing and Central Dome of' the Physical Observatory and of the new Altazimuth Pavilion was commenced last November, but has been much delayed, first by the long frost this spring and then by failure in the supply of terra cotta. The foundations of the North wing have been laid and the walls built up to the level at which the terra cotta commences. The range of wooden Offices which was partly on the site of this building has been moved to the North-west side of the Physical Observatory. The building of the new Altazimuth Pavilion is practically completed as regards concrete foundations, pier and floors, and brickwork, and is ready for thee erection of the dome, which Sir Howard Grubb has nearly completed. The heavy portions of the new Altazimuth were placed on the pier on May 6 in readiness for the mounting of the instrument as soon as the dome is erected.
As already mentioned the room under the Chronometer Room has been fitted up to give accommodation for the greatly increased number of chronometers and deck watches on trial, and plans have been prepared for a supplementary chronometer oven which is also much wanted.
During the gale of 1894 December 22 the shutter of the Astrographic Dome was torn off and blown into the courtyard. A new shutter provided with more efficient wind-guards was finished by Sir Howard Grubb on February, the shutter opening and the instrument being in the meanwhile covered with tarpaulins. The roof of the covered passage in front of the Transit-Circle Room having been damaged by the fall of the shutter, a new porch has been constructed to provide a more suitable entrance to the Transit-Circle Room.
With the courteous assistance of the Admiral Superintendent and Staff Captain at Chatham Yard, canvas sails to act as wind-screens have been fitted up on the two sides of the shutter opening of the 36-feet dome. These sails, which were completed at the end of February, are each 22 feet high by 8 feet wide, and can be hauled up or down to any required position by tackle specially arranged for the peculiar conditions of the case. They have proved to be very useful in protecting the 28-inch telescope and the observer from the wind.
Provision has been made in the Navy Estimates for the erection in Greenwich Park of a Magnetic Pavilion for absolute determinations of the magnetic elements, and the plans are now being prepared in the Director of Works’ Department. It is proposed to establish this station in the immediate neighbourhood of the Observatory, and at such a distance that there would he no suspicion of disturbance from the iron in the buildings.
A proposal is under consideration for the construction of a balcony round the octagonal building which carries the 36-feet dome, to give an all round view of the sky, which is very necessary for the effective use of the 28-inch telescope.
It is also very desirable that a water-tank with sufficient supply to drive the water-clock of the Great Equatorial for four or five hours should be provided, so that the use of the instrument should not be interfered with by occasional failures in the water-pressure from the main, and by frost, to which the present supply from the small cistern on the roof of the Octagon Room is much exposed. The proposed large tank could be advantageously placed on the flat of the lobby of the 36-feet dome, where, arrangements could be made to protect the water-supply from frost.
The completion of the electric light installation by the laying of distributing leads to the principal rooms was taken in hand on February 18, and the work, which has proved much more troublesome than was anticipated, is now nearly finished.
The Report here presented refers to the year from 1895 May 11 to 1896 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Moveable Property, and Library:–
The building of the North wing and Central Dome of the Physical Observatory has been delayed by failures in the supply of terra cotta and by labour disputes, and is still unfinished as regards plastering and carpenters' work. The Lassell dome, which was erected in the South Ground in 1884, was taken down in August and has been re-erected on the new building. The completion of the Physical Observatory by the building of the East and West wings has been sanctioned, and provision has been made in the Navy Estimates for commencing the work during the present year.
The new Altazimuth Pavilion and Dome were completed early in January, with the exception of the observing floors and moveable roofs over the collimators, which are now being made.
The building of the Magnetic Pavilion in Greenwich Park has been delayed, as the exact site has not yet been definitely settled in concert with H.M. Office of Works. In view of the great mass of iron in the new Physical Observatory it is important to select a site as near the magnetic East and West line as circumstances will admit, so that there may be no sensible deflection of the declination magnet. It is also very desirable that the enclosure should be of sufficient size to allow of the Standard Thermometers (dry and wet bulb and solar and terrestrial radiation) being transferred there in order to secure a free circulation of air, which cannot be obtained in their present position owing to the interference of the new buildings.
Provision has been made for the supplementary chronometer oven referred to in the last Report, and it is now being made.
The proposed water tank on the flat of the lobby of the 36-foot dome for the supply of water to the driving-clock of the Great Equatorial is also being made.
The construction of the proposed balcony to give an all-round view of the sky, from the building in which the 28-inch telescope is mounted, has not yet been sanctioned.
It is proposed to extend the electric light installation to the new Altazimuth and to the Thompson photo-equatorial in the new Physical Observatory, and provision has been made for this in the Navy Estimates.
Two gas stoves have been fitted up in the transit-circle room for occasional use to assist in drying the room and instrument in damp weather, especially when a thaw sets in after a long frost.
The Report here presented refers to the year from 1896 May 11 to 1897 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Moveable Property, and Library:–
The building of the North wing and Central Dome of the Physical Observatory was finished in 1896 September, with the exception of the vane on the Central Dome, which was completed last March, but the office furniture was not all supplied till April, and it has therefore been necessary to postpone the occupation of the rooms till the present time. An observing floor and gallery have quite recently been fitted up in the Dome to facilitate work with the new Thompson Equatorial, now mounted there. The completion of the Physical Observatory by the building of the East and West wings has been further delayed, though provision was made for commencing the work in the last financial year. It is hoped that it will now be taken in hand, the necessary funds having been provided. Until this building is completed the arrangements for the accommodation of the staff and of the photographic and other records are necessarily provisional.
The selection of a site in Greenwich Park for the Magnetic Pavilion has given much trouble, owing to the difficulty of finding a suitable position free from any suspicion of disturbance from iron. It has been found necessary to select a site at a greater distance from the Observatory than was originally contemplated, and, after a series of observations had been made at different stations, mainly to determine the disturbing effect of the mass of iron in the Reservoir to the South of the Observatory, a site which appears to be in every respect suitable has been found on the East side of the Observatory at a distance of between 300 and 400 yards. [This site has been approved by H.M. Office of Works, since the date of this Report.]
The observing floor and moveable roofs over the collimators of the new Altazimuth, the supplementary chronometer oven, and the water tank on the flat of the lobby of the 36-foot dome for the supply of water to the driving-clock of the Great Equatorial, which were in progress at the time of the last Report, were completed in September.
Provision has been made in the Navy Estimates for extending the electric light installation to the completed portion of the Physical Observatory and to the new Altazimuth Pavilion.
The construction of the proposed balcony to give an all-round view of the sky from the building in which the 28-inch telescope is mounted has now been sanctioned.
The Report here presented refers to the year from 1897 May 11 to 1898 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The completion of the Physical Observatory by the building of the East and West wings, for which funds were provided in the Navy Estimates for 1896, was not taken in hand till 1897 October. The work is now proceeding, though delayed by failure in the supply of terra cotta. Heating apparatus to warm the whole building by means of hot air has now been fitted up, but it was not available during, the winter, its completion having been delayed till the latter part of March.
No progress has been made with the construction of the Magnetic Pavilion, which is urgently required, and for which provision was made in last year's Navy Estimates. The site selected on the east side of the Observatory, at a distance of about 350 yards, was approved by Her Majesty's Office of Works, who were prepared to hand it over formally last October. The drawings of the building were ready early in October, but the contract for its construction was not entered into till early in May, just before the date of this Report. It is hoped that no further delay will now occur, and that the building will be completed this summer.
Provision was made in last year's Navy Estimates for the erection of a balcony round the building- in which the 28-inch telescope is mounted, so as to give an all-round view of the sky, and after the plans had been prepared, scaffolding was put up last February in preparation for the works. The plans, however, were subsequently reconsidered and largely modified, and the work has not yet been commenced.
The electric light installation has been extended to the Physical Observatory, and the Altazimuth Pavilion, and telephone communication between the office rooms in the old and new buildings of the Observatory respectively has been provided by the Post Office.
Provision has been made for an Accumulator House to take the place of the shed in which the accumulators are now placed, and it has been arranged to construct this as a basement on the north-east side of the Physical Observatory, where it will be conveniently placed for connecting with the electric mains.
The Report here presented refers to the year from 1898 May 11 to 1899 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The new Observatory Building which has been in progress since 1891, was completed last March, by the addition of the East and West wings. This handsome building, which has been skilfully designed by Mr. Crisp, under the superintendence of the Director of Works of the Admiralty, provides much needed accommodation for the Observatory Staff, for the photographic records and books of calculations, and for the library, which had long outgrown the rooms hitherto available for it. In the new Observatory Building – which is cruciform in shape, having four wings of three storeys, with a central tower carrying the Thompson Equatorial and Dome – the Staff occupies the principal floor, the library will be placed in the ground floor of the North, East, and West wings, the ground floor of the South wing being fitted up as a workshop, and the upper floor will accommodate the photographic and other records and the stock of publications of the Observatory. Office furniture for the whole building has now been supplied through the Director of Stores, and as regards the library, records, publications, &c. arrangements have been made with Messrs. Lucy & Co. for the supply of their patent adjustable book-stacks to provide the shelf space required.
The completion of the new Observatory Building, which at three points breaks into the existing boundary fence, makes it desirable that the boundary of the Observatory should be enlarged in order to show off the handsome new building and a proposal to give effect to this is under the consideration of the Admiralty. In the meanwhile, as a temporary measure, the existing wooden fence has been repaired where necessary.
Several sheds and outbuildings which encumbered the grounds have lately been removed consequent on the completion of the new building, in which provision is made for their contents.
The new Magnetic Pavilion, in an enclosure in Greenwich Park, at a distance of about 350 yards from the Observatory, on the East side, was completed at the end of last September, and the magnetic instruments for absolute determinations have been installed there. The greatest care has been taken to exclude all iron in building, the Magnetic Pavilion, and the site has been selected so that there is no suspicion of magnetic disturbance from iron in the neighbourhood. The enclosure also provides a good meteorological station, where, the standard thermometers and rain-gauges have been mounted.
The balcony round the building in which the 28-inch telescope is mounted was completed at the end of September, and is found very useful by the observers in doubtful weather, as giving an all round view of the sky.
The new Accumulator House, to take the place of the shed in which the accumulators are now placed, has been built as a basement on the north-west side of the new Observatory Building. It was completed at the end of March.
The electric light installation has been extended to the East and West wings of the new Observatory, and provision has been made for the renewal and enlargement of the accumulators, which will, as soon as practicable, be placed in the new Accumulator House and connected with the dynamo and electric mains.
The room formerly used as the Astronomer Royal's Official Room has been converted into an additional Chronometer Room, and has been fitted up with long tables or shelves to accommodate 140 chronometers.
The Report here presented refers to the year from 1899 May 11 to 1900 May 10, and exhibits the state of the Observatory on the last-named day. The date of presentation of the Report this year has been deferred somewhat owing to the absence of the Astronomer Royal in Portugal for the observation of the total eclipse of the Sun.
I. – Buildings and Grounds, Movable Property, and Library:–
Provision has been made in the Navy Estimates for a new boundary fence with open iron railing round the new Observatory Building, and it is proposed to extend the boundary of the Observatory grounds in order to show off the new building & effectively. The plans are now under consideration.
Provision has also been made for a new fire main and hydrants, the existing water service being inadequate in case of serious fire.
A new accumulator battery of greater capacity was supplied in March by the Chloride Electrical Storage Syndicate to replace the old battery, which was worn out.
It is proposed to extend the electric light installation to the Library rooms in the basement of the new Observatory Building.
The Report here presented refers to the year from 1900 3 May 11 to 1901 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable -Property, and Library:–
No decision has been arrived at as to the extension of the Observatory Grounds, proposed in order to provide more space round the new Observatory Building, an open iron railing being substituted for the closed wooden fence. Provision for this work was made last year in the Navy Estimates.
The improvements in the fire extinguishing arrangements at the Observatory which provision was made in the Navy Estimates for the last two years, have not yet been carried out, though the question, which was raised in 1898, was fully discussed in 1898 December, and details settled. The details were again settled last February, but the work has not yet been commenced.
Provision was made in last year's Navy Estimates for an ornamental vane for the new Altazimuth Pavilion, and it is understood that the work has now been put in hand.
The extension of the electric light installation to the Library rooms in the basement of the New Observatory was carried out last October.
The S.E. Lobby on the upper floor of the New Observatory has been fitted up as a new photographic developing room, available for large plates.
The triennial exterior painting of the Observatory buildings is now in progress.
A "Rapid Rectilinear" lens of 4 inches aperture and 33 inches focus has been obtained for stellar photography and for use in eclipse observations.
The Report here presented refers to the, year from 1901 May 11 to 1902 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The question of the provision of an open iron railing with extension of the boundary round the new, Observatory building in substitution for the present unsightly wooden fence still remains unsettled. Meanwhile, provision has been made for putting the Observatory grounds in order after the disturbance caused by the erection of the new buildings, and this work has been carried out as far as the present cramped conditions would allow.
The improvement in the fire and water service of the Observatory, for which provision had been made as mentioned in the last Report, has now been carried out. A new 6-inch main has been laid by the Admiralty from the Water Company's main on Blackheath to the Observatory, with fire hydrants commanding the buildings, and smaller hydrants in various parts of the Observatory buildings and domes. A branch pipe, with hydrants, has been carried to the Magnetic Pavilion enclosure. The work was commenced early in December and finished in February, but the fire hose for use with the various hydrants was not supplied till after the date of this Report.
A fire alarm for telephonic communication with the Borough Fire Station in Greenwich has been set up by the Post Office authorities in the. Front Court of the Observatory, but it is not yet in connection with the Fire Station.
The ornamental vane for the Altazimuth Dome, mentioned in the last Report, was completed last June.
The triennial exterior painting of the Observatory buildings which was commenced in the spring of 1901 is not yet completed. The painting outside and inside of the Altazimuth Pavilion and Dome was taken in hand in January, but the work on the Magnetic House, Offices, and New Observatory was delayed so long that it has now become necessary to defer it till the autumn.
Circulating tanks for use with the gas-engine were fitted up in January, and the gas engine, which has been continuously in use for eight years, was thoroughly overhauled and repaired by Messrs. Crossley last March.
The Report here presented refers to the year from 1902 May 11 to 1903 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The improved fire and water service of the Observatory was completed shortly after the date of the last Report, by the supply of fire hose for use with the various hydrants, and of a telephonic fire alarm.
[Since the date of this Report the telephonic communication was put out of action by lighting, during the thunderstorm of May 17, and is now being restored.]
The N.E. Lobby on the upper floor of the New Observatory has been fitted up as an additional photographic room for use in conjunction with the S.E. Lobby in the photographic publication of the Astrographic Chart.
A partition has been put up in the Office Room used by the Astronomer Royal and Chief Assistants, to provide a separate room for the former.
A portion of the boundary fence on the west side has been renewed, a retaining wall being built to support it.
The triennial exterior painting of the Observatory buildings which was commenced in the spring of 1901 was completed last November.
Electric lamps have been fitted up to light the entrance to the new Observatory building, and the passage from the old Observatory to the Altazimuth Pavilion and other buildings.
The Report here presented refers to the year from 1903 May 11 to 1904 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, -Movable Property, and Library:–
The Lower Computing, Room has been partitioned off from the staircase leading to the Upper Room and Dome, as much inconvenience was felt from draughts by the staff employed there, especially during the winter.
The whole of the New Observatory Building was painted internally last autumn with the exception of the East and West Library Rooms, which remain at present as originally distempered. The Magnet House and the old Record Rooms were also painted internally during the summer.
The Report here presented refers to the year from 1904 May 11 to 1905 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The accumulators for the electric light were renewed in November, the new batteries being erected on November 28, and brought into use on December 1.
Standards for the electric lamps outside the New Observatory building were supplied and fixed in March.
The oak fencing on both sides of the pathway, from the Great Equatorial as far as the Altazimuth, was renewed during January and February.
The domes of the Astrographic, Sheepshanks, and Great Equatorials, and of the Altazimuth and Transit Pavilions were painted externally during the months of October and November.
Three new book cases have been supplied and fixed in the South wing of the New Observatory (principal floor). A treble extension ladder for use in the domes and buildings has been purchased.
The Report here presented refers to the year from 1905 May 11 to 1906 May 10, and exhibits the state of the Observatory on the last-named clay.
I. – Buildings and Grounds, Movable Property, and Library:–
The painting (external and internal) of the Observatory buildings, which had fallen much into arrear owing to insufficient provision of funds in recent years, has now been taken up energetically, and is progressing well.
A defective drain from the Old Observatory building has been reconstructed, and other sanitary improvements have been made.
In preparation for the Eclipse Expedition last August, four new portable canvas-covered huts were made and two others were reconstructed. These were all brought back after the eclipse, and are stored for future occasional use.
A permanent storehouse for portable instruments, huts, chronometer baskets, and general stores, is much needed to take the place of the existing wooden sheds, which have various disadvantages, the most serious being the risk of fire. A suitable site for this could be found on the south-west side of the New Observatory, where the slope of the ground gives facilities for the erection, at comparatively small cost, of a partly sunk basement, which would not interfere in any way with the New Observatory building.
The Report here presented refers to the year from 1906 \May 11 to 1907 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The painting (external and internal) of the Observatory buildings, which was in progress at the date of the last Report, was practically completed last November.
A new porch and covered glass passage have been erected in front of the Astronomer Royal's official residence in substitution for the old porch and passage, which required renewal, and a new and wider pathway has been laid in granolithic cement in front, leading from the Old Observatory building to the Chronograph room.
The cross-trees of the Time Ball mast have been renewed.
The lightning conductors from the Octagon room roof and from the Magnetic Pavilion have been connected to distant water mains, so that there would in the former case be no risk of interference with the earth connections of the time-signal and other telegraph circuits of the Observatory.
Provision has been made in the Navy Estimates for the permanent storehouse for portable instruments, huts, chronometer baskets, &c., referred to in the last Report, and plans for the building have been prepared.
The Report here presented refers to the year from 1907 May 11 to 1908 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The building of the new Storehouse for portable instruments, chronometer baskets and general stores, referred to in the last two Reports, was commenced at the end of January and having been pushed on rapidly is now practically completed. The wooden sheds formerly in use have been removed and the ground round the new Storehouse has been fenced in with unclimbable iron railing.
The covered passage with corrugated iron roof in front of the Old Observatory building required renewal and has been replaced by a new structure with glass roof. Granolithic cement has been substituted for the old stone pavement.
A circular railing round the shutter platform on the dome of the 28-inch refractor has been filed to facilitate work on the dome, when necessary.
A new greenhouse has been erected to replace the old one which was past repair.
The domes have been painted in the course of the year, and at the same time the 28-inch, Thompson and Astrographic Equatorials and the Altazimuth have also been painted.
The collection of Portraits (prints and photographs) in the Octagon Room has been reframed where necessary, the old frames being bad state.
The Report here presented refers to the year from 1908 May 11 to 1909 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The new fireproof Storehouse was completed just before the last Visitation, and the inflammable and other stores, which were formerly in wooden sheds, have been removed to this building.
The canvas wind-screens which were fitted up in 1895 on the opposite ends of the shutter-opening of the 36-feet dome to protect the 28-inch telescope and the observer from the wind, have been renewed by arrangement with the Admiral Superintendent at Chatham Dockyard.
The vertical shutters on the south side of the Transit-Circle Room have been renewed.
The walls and floor of the developing room in the S.E. attic of the New Observatory building have been covered with sheet lead to protect them from the corrosive action of the chemicals used in the photographic work for the reproduction of the Astrographic Chart.
The Report here presented refers to the year from 1909 May 11 to 1910 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
Additional accommodation for the storage of the Greenwich and Cape Observatory Publications having become necessary, eight double sets of shelves have been erected in the storehouse.
New spring contacts have been fixed to all the lighting conductors of the domes.
A new 4-inch gas-main to the Observatory was laid in October. The 3-inch main by which the gas was formerly supplied, was liable to frequent interruption through choking; this was a source of considerable inconvenience, involving the interruption of magnetic and meteorological registers, and the failure of the heating of the chronometer-ovens.
The periodical painting of the domes and external parts of the buildings is now in progress.
The Report here presented refers to the year from 1910 May 11 to 1911 May 10, and exhibits the state of the Observatory on the last-named day.
Sir W. H. M. Christie resigned his office on 1910 October 1, and a portion of the observations here referred to were made under his superintendence. There seems to be no occasion to separate these from the remainder, as the course of observation has been continued without essential alteration.
I. – Buildings and Grounds, Movable Property, and Library:–
The painting of the domes and external parts of the buildings referred to in the last report was completed on June 13.
The dome of the old Altazimuth was altered in January and February so as to make it suitable to hold the Dallmeyer Photoheliograph.
During February brick piers were built and rails laid on them to carry a new mercury trough for the New Altazimuth.
In response to the Astronomer Royal's request for additional bedroom accommodation, alterations in the official residence were begun on March I and are now in progress. The new rooms are being made under those on the west side of the house, and H.M. Office of Works have kindly allowed the path in the park to be moved 8 feet away and an iron fence to be erected. The extension was made in this way in preference to building above the rooms on the south side, because two of the windows of the Octagon Room would have been partially obstructed if the latter plan bad been adopted.
The Public Standards of Length affixed to the outside wall of the Observatory were sent to the Standards Department on December 16 for repair and adjustment. They were returned and remounted on February 9.
The Report here presented refers to the year from 1911 May 11 to 1912 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The alterations in the Astronomer Royal's official residence were completed in September. They include the provision of three new rooms under the rooms already existing on the West front, the installation of a heating apparatus, the extension of the electric light and a number of minor alterations.
The same system of heating was applied to the Octagon room. Electric light was substituted for gas, and the room was repainted. The Octagon room is now used as a reading room in which the current Astronomical literature may be referred to.
The strong room to the west of the Lower Computing Room was altered between July and November to make it serve as a clock room. A second wall was built separated from the outside walls to the West and South by an air space, and double doors were provided. The necessary extensions and alterations of the electric cables were carried out by the Engineering Department of the General Post Office during the latter part of October and early part of November.
As the heating arrangements of the chronometer rooms under the Great Equatorial by a stove and of the record room by a hot-air supply were unsatisfactory and had become obsolete, a system of hot-water pipes and radiators was installed.
At the same time the spiral staircase in the record room was removed, and the upper room divided from the lower, a new entrance being made from one of the rooms of the old library. These alterations, which make a substantial addition to the room available for shelves, were completed in March.
The observing hut of the Zenith Telescope of the late Mr. Bryan Cookson, kindly presented by the Cambridge Observatory, was brought from Cambridge and erected in the front Court by the side of the Longitude Pavilion in the first week in August.
The internal painting of the new Observatory was commenced in November and is completed with the exception of the dome.
Four boxes in the Observatory grounds and four in the grounds of the Magnetic Pavilion were fixed near the hydrants during April, to hold the fire hose.
The Report here presented refers to the year from 1912 May 11 to 1913 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
A number of repairs rendered necessary by the discovery of decayed beams on the -west side of the transit circle room, and in the floor and on the roof of the octagon room, have been executed during; the year by the Works Department.
Some alterations have been made in the small rooms in the old Altazimuth building, one being converted into a developing room for use with the photoheliograph, and the other into a spare room for clocks.
The computers' cloak room has been enlarged by the removal of the iron partition.
The arrangements for drainage of the front court were reconstructed in December.
A new iron cupboard was fixed in the lower Record room to house the Parliamentary Copies of the Imperial Standards of Weight and Measure. Additional book-racks have also been fixed in that room.
The internal painting of the Altazimuth and the Store-room was carried out in September. The internal painting of the Old Observatory is in progress.
The Observatory has ceased to generate its own electric current for lighting and other purposes, and now obtains current from outside. The gas engine and dynamo will shortly be removed, and the battery of accumulators has already been taken away. Alternating instead of direct current is now used, and a small supply of direct current is obtained by means of a rotary converter. The direct current is required for charging small storage batteries (used in lighting the instruments) and for the electro-magnet used in magnetic tests of chronometers and watches.
Eight additional fire-buckets and two stand-pipes with swivel heads have been purchased.
The Report here presented refers to the year from 1913 May 11 to 191.1 .May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
A new building has been erected in the Magnetic Enclosure the Park for the purpose of housing a set of modern instruments for recording the variations of the magnetic elements. The building was constructed by tile Works Department of the Admiralty, and consists of a thickly-walled outer room containing all inner room, well insulated by a considerable air-space. To maintain the constancy of the temperature, electric heaters, controlled by a thermostat, are being installed. The building was completed in March, the cable to carry the current was laid in April, and the arrangements for heating are nearing completion.
The minor works necessary for the repairs and maintenance of the buildings carried out during the year by the Works Department include the reconstruction of the drainage of the Magnet House, Central Store, and East Wing of the New Observatory, and the re-pointing of a considerable amount of tile brickwork of the Old and New Observatory. The external painting of the Observatory was commenced in April and is now well advanced. The internal painting of the Old Observatory was completed on July 30.
Fire hydrants, with the necessary hose pipes and nozzles have been fixed in the Central Store and in the basement of the Magnet House.
A motor generator has been installed to obtain continuous current front the town supply, for the purpose of small storage batteries used for lighting the instruments and for other purposes. The gas-engine, dynamo, and accessories formerly used for lighting have been removed to the Royal Marine Infirmary at Deal. Two small motors have been supplied to rotate the dome of the Thompson Equatorial and to wind the clock-weight.
The Report here presented refers to the year from 1914 May 11 to 1915 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The electric heaters, controlled by a thermostat, for maintaining a constant temperature, have been installed in the new magnet house, and are working very satisfactorily. Some minor works, including the fixing of lightning conductors, were finished in July.
For the better protection of the Observatory from fire two new hydrants have been fixed by the Metropolitan Water Board in the 12-inch main which runs across the foot, of the hill North-West of the Observatory.
The lamp lobby and a small room adjoining it, previously used as a store room, have been converted into a room for the transit-circle chronograph which has been transferred from a room on the North side of the court-yard. The external painting of the domes was carried out during February and March.
In view of the success which has attended the underground meridian marks at the Cape Observatory, borings were made just outside the S. collimator of the transit circle, and at the end of the Astronomer Royal's garden. The first of these was stopped at a depth of 37 feet after passing through 29 feet of very hard compact ballast. Throughout the last 24 feet it was necessary to use chisels almost continuously before the core could be removed with an augur. It was considered that this formation was very suitable for the construction of a collimator pit of relatively shallow depth. The boring in the garden, which is about 40 feet below the level of the ground near the transit circle, indicated an entirely different formation. The bore was sunk to a depth of 58 feet in 8 days, the last 42 feet being in very fine dry sand in consultation with the Civil Engineer the conclusion was reached that it was useless to proceed further, as absolute stability of a mark could not be anticipated, especially as well shaft would form a channel by which surface water could reach and probably disturb the sand.
The Report here presented refers to the year from 1915 May 11 to 1916 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
No alterations or additions to buildings have been carried out since 1915 May 10. The smaller domes were painted externally in April. The painting of the domes of the 28-inch and Thompson Equatorials has been deferred.
The Report here presented refers to the year from 1916 May 11 to 1917 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The Thermograph Stand has been removed to the Magnetic Enclosure in the Park. No other changes have, been made in the buildings beyond a few small necessary repairs. The external painting of the domes of the 28-inch and Thompson Equatorials, which had been deferred will be shortly put in hand.
[The Silvertown chemical plant (owned by Brunner, Mond & Co and adapted for the production of trinitrotoluene (T.N.T.) in 1915), caught fire just before 7am on 19 January 1917, resulting in the detonation of 50 tons of high explosives. A large part of the factory was instantly destroyed and according to Margaret Wilson, (Dyson’s daughter), the plate glass window of the Octagon Room caved in (Margaret Wilson: Ninth Astronomer Royal, The Life of Frank Watson Dyson, Cambridge, 1951 p 184). She also states (without giving dates) that during the war: a range finder was installed on roof of old magnetic observatory (p 183), an incendiary bomb (unexploded) near the gates (p 183) & that “except for a bit of fence that was burnt in the first air raid and a few shrapnel splinters which penetrated the papier mâché domes, the Observatory was unharmed by the raids (p182). It would appear that the plate glass window was replaced with a sash (survey of London, Vol 5, London east, 1930)]
The Report here presented refers to the year from 1917 May 11 to 1918 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the domes of the 28-inch and Thompson Equatorials was carried out in the summer of 1917. At my request the Civil Engineer kindly made a thorough survey of the state of repair of these domes. He reported that, broadly speaking, they were both found to be in an excellent state of preservation, which is undoubtedly attributable to their frequent painting. Several small repairs have been made to these domes, the Astrographic dome, and that of the longitude pavilion.
A commencement has been made towards the demolition of the Magnet-House, a wooden building erected in 1838 and now superseded by the buildings in the Magnetic Enclosure. The fittings have been made use of elsewhere in the Observatory, and parts of the building are being used in the construction of a small wooden hut now being erected in the Magnetic Enclosure. This hut will house the Electrometer, the only instrument which had not been already transferred from the Magnet House.
The Report here presented refers to the year from 1918 May 11 to 1919 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the old part of the Observatory was completed on 1918 August 31. This included the Astrographic, Sheepshanks, Transit Pavilion and Altazimuth domes.
The roof of the Transit Circle was found to be defective and was repaired on September 28.
The demolition of the old Magnet House has been completed. The small wooden hut for the electrometer, referred to in the last report, has been erected in the Magnetic Enclosure. All the instruments for the determination of magnetic elements and their variations, the determination of atmospheric electricity, the barometer, recording barograph and thermometers, thermograph and rain-gauges are installed in this enclosure.
The renewal of the Time-Ball, referred to in the Report for 1914, but postponed on account of the war, has now been taken in hand, together With structural repairs needed to the Ball Turret. A new ball of aluminium, a new winch and part of the raising machinery, supplied by Messrs. E. Dent & co., and, a new teak mast, constructed by the Works Department of the Admiralty, have been at the Observatory since 1914. The installation of the new apparatus and repairs of the turret are now in progress, the old Time-Ball having been put out of use on April 14 and dismounted.
The Report here presented refers to the year from 1919 May 11 to 1920 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Astrographic, Sheepshanks, Altazimuth, and Thompson domes, the Transit Pavilion, the New Building, and the covered way of the Front Court, was commenced on April 10 and is nearly completed.
A number of structural repairs have been made in the Octagon Room building. The ball turret has been strengthened and partly rebuilt. New struts have been fixed to support the mast of the time-ball. The woodwork at the top of the staircase leading into the Octagon Room was found to have rotted. The lintel has been replaced by one of concrete, and the side walls have been replastered.
Repairs have also been made to the roof of the Central Store Room.
With a view to extending the range of reception of the Wireless Time Signals a new aerial was made at the Observatory during August. The aerial is of the two-wire type and consists of 7 strand No. 19 gauge phosphor-bronze wire with separators three feet long. Its erection was supervised by the Civil Engineer of the Royal Naval College. The length is 160 yards from the western Corner of the New Observatory to the Octagon Room and a lead-in of 40 yards to the wireless room under the Sheepshanks dome.
The new aluminium time-ball was fitted in position on the turret on June 16, and the first trials of raising and dropping the ball were made on August 15. The Winch for raising the ball has been removed from the small recess near the Octagon Room and is placed in the small room on the ground floor near the trigger apparatus. Part of the dead weight of the ball has been taken off the locking surfaces of the clips by introducing a counterpoise of 1 cwt., arranged in the ball turret. The new ball was brought into use on August 23, and the installation completed by Messrs. E. Dent & Co. on September 12.
The substitution of electric instead of gas heating in. the chronometer ovens was commenced on April 12 by Messrs. Grundy &- Co. and is now in progress. Low-power beating elements, controlled by a thermostat which operates an automatic switch, are placed in the same chambers as the chronometers and watches.
Much of the fire hose was found on the official inspection to be defective, and renewals of the defective pieces have been made.
The Report here presented refers to the year from 1920 May 11 to 1921 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Astrographic, Sheepshanks, Altazimuth, and Thompson domes, the Transit Pavilion, the New Observatory, and the covered way of the Front Court, was completed on May 25.
A number of minor repairs to the buildings have been made during the year, including a chimney stack on the Octagon Room, which was considered unsafe and was rebuilt, and a cornice on the roof of the Record Room.
A slow combustion stove has been substituted for the open stove in the Central Store, and the ventilation altered so as to ensure a greater circulation of the hot air.
The substitution of electric for gas heating in the chronometer ovens was completed in June. The temperature control works quite satisfactorily and within a close range. It is a great advantage to have got rid of the gas fumes which frequently found their way into the Chronometer Room.
For the purpose of testing chronometers and watches at low temperatures at any period of the year, a refrigerating plant was installed by Messrs. Hall & Co., of Dartford, in January. The plant consists of a suitably lagged chamber, 7½ ft. X 6½ ft. X 6½ ft., with shelves for 45 chronometers, cooled by a brine tank reduced to a low temperature by the expansion of liquid carbon dioxide in a coil immersed in the brine. The compressor is worked by a 3 horse-power single phase motor.
A 6½ -inch self-contained motor-driven lathe, with a ¼ horse-power motor and accessories, has been supplied to the workshop. The lathe was installed and brought into use in March and has already been of considerable service.
A milling machine has been received from the Disposals board, but has not yet been installed.
The internal wiring of the Observatory has been taken over by the Admiralty from the General Post Office as from April 1.
The Report here presented refers to the year from 1921 May 11 to 1922 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Magnetic Pavilion, Central Store and Sheds was completed on 1921 July 2.
Renewal of the roof of the staircase of the 28-inch Dome was finished on 1921 December 23.
Portions of woodwork supporting the Robinson Anemometer House which were found to be defective have been renewed. Further repairs to the Anemometer House itself will have to be undertaken in the near future.
Some of the lead work on the roof of the Octagon Room has been replaced and the Octagon Room has been redecorated.
When the support to the Thermometer Stand in the Front Court was being renewed on February 23 the Stand was moved a few feet into a more open position and is now practically on the Meridian. A new Thermometer Stand was erected in the garden, south of the Transit Circle on March 27.
The Astrographic Telescope was dismounted oil 1921 July 4–8 and parts sent to Sir Howard Grubb, at St. Albans, to have the necessary alterations made to suit them for the latitude of Christmas Island (10° S.). It was mounted on the south ground of the Observatory on 1921 November 9, and, after being tested, dismounted on December 17. It was then packed and despatched on 1922 January 20. The object-glasses were taken personally by the observers on January 28.
An aluminium camera to carry the 40° prism lent by the Joint Permanent Eclipse Committee was completed and mounted on the 30-inch reflector on 1921 September 29.
The voltage of the electric light supply was changed from 110 volts to 220 volts on 1921 November 17. The current supplied to the Magnetic Pavilion and part of that used for power remains at 110 volts.
In the Report for 1921 it was mentioned that the maintenance of batteries and internal wiring of the Observatory for clock, observation, and time-signal circuits had been transferred from the Post Office to Admiralty charge. During the year the electrical engineer, Chatham Dockyard, has carried out the renewal of the wiring and substituted a central accumulator battery in place of separate dry cell batteries for each circuit.
Certain portions of the wiring of the Observatory had been in use nearly forty years, from the time the G. P. O. took over maintenance, and the last renewal of any part of the wiring was carried out in 1905. At that time it was found necessary to renew the wires between the S. E. Dome and the Altazimuth. The cables then brought into use were carried in casing on the top of the closed wooden fence dividing the footpath connecting the old and new buildings from the Observatory grounds. The cables now brought into use have been placed in an underground duct through this section, and advantage has been taken of this to remove the fence, so leaving the whole Observatory grounds more open.
The wiring in the Clock Room has been left as installed in 1911, the connections to the new wiring being made on a small through junction board near the door of the room. With the exception of the short length of wire in the Clock Room, the conductors throughout the Observatory are homogeneous and are carried in lead-cased cables, the insulation being composed of an enamel coating and a wrapping of waxed cotton.
The general scheme of the circuits has not been altered to any considerable extent, but the substitution of higher resistance relays in two of the primary clock circuits should be advantageous.
A small room on the ground floor, under the photoheliograph dark room, has been utilised for the battery room instead of the basement under the Ball Lobby.
Two sets of eighteen accumulators have been installed, arranged so that one set can be substituted for the other as occasion requires. The total voltage of 36 is used hourly for the Post Office signal and twice a day for the signal from the Westminster clock. For the Observatory Circuits lower voltages are employed and these are obtained by tappings taken off the battery at suitable positions. The grouping of the cells has been arranged to secure as far as possible an equal output from each cell. A compound change-over switch is provided for changing one set of accumulators for the other, the contacts being arranged that no break in circuits occurs during the operation. A control board for charging the accumulators in position has been provided, the necessary direct current being supplied by the motor generator already in use at the Observatory.
The various battery leads are connected to blocks mounted on a test frame in the Lower Computing Room near the Time Desk. From this point the supply of current is obtained for the various circuits operating. In addition to carrying strip connections to all circuits, sixteen relays are also mounted on the test frame. Normally twelve of these are in use on the Standard Sidereal Clock, hourly signal, minute signal and acknowledgement signal circuits.
The Report here presented refers to the year from 1922 May 11 to 1923 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the domes of the 28-inch, Astrographic and Sheepshanks equatorials and of the Transit Pavilion was completed on 1922 October 31. The inside of the 28-inch dome was painted in November.
The main gate to the Observatory which had been repeatedly repaired was taken down in January and replaced by a somewhat lighter one.
The painting of the external woodwork of the older part of the Observatory was commenced on February 28 and is nearly completed.
The Reflex-Zenith tube has been dismounted and placed in the lower Museum. The wood-work in the room has been dismantled and the floor repaired. It is proposed to use the room as a store for stationery, &c.
The instruments taken by the observers to Christmas Island reached the Observatory on December 4. The Astrographic equatorial was cleaned and remounted by December 30.
The instruments left at the Pulkovo Observatory in 1914 owing to the outbreak of war arrived back safely on 1923 April 17. The Quartz Spectroscope kindly lent by the Solar Physics Observatory has been returned to Cambridge. The Coelostats belonging to the Eclipse Committee and the Royal Astronomical Society are being temporarily housed at the Observatory.
A new Rivett Precision Lathe, motor driven, has been supplied. With the 6½-inch lathe and milling machine supplied in the spring of 1921, the workshop is now adequately fitted for the demands which are constantly made on it. At the present time a photometer of the Hartmann type is being constructed.
The Report here presented refers to the year from 1923 May 11 to 1924 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the dome of the Thompson Equatorial was completed on May 23.
The Record room was cleaned and redecorated in the autumn.
Considerable repairs have been carried out on the roof of the Octagon room. A new floor has been provided for the wooden house of the Robinson Anemometer. The balustrade round the roof has been thoroughly overhauled and repaired. This work which involved some structural alteration is now completed. The building of the Magnetic Observatory at Abinger was commenced in January and has made good progress. It is dealt with in greater detail in Section III. of the Report.
III. – Magnetic Observations–
New Magnetic Observatory.-The approaching electrification of the railways in the neighbourhood of Greenwich made the removal of the magnetic observatory to another site necessary. In choosing a new site the conditions were laid down that it should be as near as possible to Greenwich, so that the new Observatory may be an out-station and kept in close touch with Greenwich by regular visits from the Superintendent. of the Magnetic and Meteorological Department. It should also be sufficiently distant from existing railways to be unaffected should they be electrified, and in a place where, as far as can be foreseen, no extension of railways will be made. The site selected consists of 10 acres of land on the side of the valley known as Abinger Bottom, near Leith Hill, in Surrey. The geographical position is Lat. 51º 11' 3" N., Long. 0º 23' 12" W. The height above sea-level is 800 feet. The distance from the nearest railway line is 2¾ miles. The distance from Greenwich is 26 miles.
The land for the Abinger Observatory was acquired late in December, and building wag commenced early in January. The suitability of the site for a magnetic observatory was assured by observations made in September by Mr. Jones and Mr. Witchell. The buildings will be similar to those now in use at Greenwich, and consist of a wooden pavilion for absolute observations, and a house enclosing an inner chamber with thermostatic control for the magnetographs. In addition, there is a house for a resident observer, and one for the caretaker, and adjoining it an office room and- a house for the dynamos and accumulators. The minimum distance from the dynamo room to the houses containing the instruments is 370 feet.
The machinery, which is required for pumping water, lighting and heating, consists of two direct-current dynamos driven by petrol motors, accumulators, and motor-alternators to transform power from the accumulators into alternating current, rendered necessary by its use in the Magnetograph and Absolute buildings. The dynamos are sufficiently far from the magnets to need but little shielding. The instruments will be similar to those now in use at Greenwich. In addition to these we hope to have a coil magnetometer of the Schuster-Smith pattern on loan from the National Physical Laboratory.
In order that simultaneous observations at Greenwich and Abinger should be commenced as early as possible, the Wooden Magnet House for the absolute instruments was built first. The instruments for declination and horizontal force were installed on March 24, and a dip-circle temporarily, pending the delivery of the dip-inductor. Since this date absolute observations have been made each day with the exception of Sundays and the Easter holidays.
Good progress is being made with all the buildings, and it is expected that the machinery and lighting and heating systems will be installed and the Magnetographs set up during the summer.
The Report here presented refers to the year from 1924 May 11 to 1925 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Astronomer Royal's house, of the domes of the Astrographic, 28-inch and Sheepshank's Equatorials, of the Altazimuth and of the Transit Pavilion was completed on 1924 Oct. 15.
A cellar underneath the Octagon Room has been rendered suitable for a standard clock referred to in a later section. This room was chosen on account of its very thick walls and freedom from temperature changes. The room was rather damp, the moisture apparently coming through the thick outside wall. It was thought that this was due to wet percolating between the tiles on the north terrace. These were taken up, and a layer of concrete 6 inches thick placed underneath and the tiles relaid. The work was completed by February 13, but the room is not yet sufficiently dry.
One of the chimneys of the house was partly pulled down and rebuilt during April and May.
The building of the new Magnetic Station at Abinger was completed during the year. It is described in greater detail in a later section of the Report.
The Report here presented refers to the year from 1925 May 11 to 1926 May 10, and exhibits the state of the Observatory on the last-named day.
An event of exceptional interest to be reported this year is the celebration in July of the 250th anniversary of the foundation of the Observatory. Their Majesties the King and Queen graciously paid a visit to the Observatory on July 26. In commemoration of his visit His Majesty has kindly presented a signed portrait of himself, which has been hung in the Octagon Room. By a happy coincidence, the Meeting of the International Astronomical Union was at Cambridge this year, so that we were honoured by the presence of many distinguished foreign astronomers on this occasion. In the evening a reception was given by the President and Council of the Royal Society. On July 27 a number of guests were entertained at an official luncheon given by H.M. Government, at which the First Lord of the Admiralty took the chair.
1. – Buildings and Grounds, Movable Property, and Library:–
Between May 25 and July 18, 1925, a number of rooms were repainted. These include the Transit Circle room, the South room and staircase in the New Building, and the inside of the Thompson dome. The external painting of this dome was commenced on March 16 and completed on April 6. The external painting of the New Building is in progress.
The historic instruments in the Transit Circle room were removed for the painting, and the opportunity was taken to clean and to varnish or repaint them.
The walls and floor of the cellar under the Octagon room, in which the Standard Clock is mounted, have been rendered with a waterproof cement. Ventilation by a four-inch shaft extending to the roof of the building has also been arranged. Nevertheless, the cellar remains damp. As the clock is in a sealed case, moisture in the atmosphere, though inconvenient, has no effect on the clock. The room has been found very suitable for a standard clock both on account of the substantial foundation on which the clock is mounted, and also of its freedom from rapid changes of temperature.
The masts supporting the wireless aerial have been renewed. The aerial has been raised about 6 feet and a single wire has been substituted for a double one.
The Report here presented refers to the year from 1926 May 11 to 1927 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the New Building was completed on 1926 June 4 and that of the Altazimuth Building on November 4. The domes of the Photoheliograph, Transit Pavilion, Altazimuth, Sheepshanks and 28-inch Equatorials were painted during the summer of 1926. Some of the woodwork of the North-East Turret of the New Building was renewed in May 1927. Work was commenced on April 7 to make the room under the Shuckburgh Dome suitable for the installation of the Mean Solar Clock and Signalling apparatus which will be required for sending time-signals from the Rugby Wireless Station. The room is being protected as far as practicable from sudden changes of temperature. As the building is old, some structural defects were found which had to be remedied, making the preparation of the room longer than was anticipated.
The Admiralty have made arrangements with the Hurtwood Water Company to secure in perpetuity an adequate supply of water for the Abinger Magnetic Station.
An enlarging camera has been obtained with a large 14-inch condensing lens and a camera with bellows extension of 6 feet. This will enable enlargements to be made to the extent of 5 diameters. The photographic objective is a Cooke whole-plate lens of 2 inches diameter and 11.2 inches focus.
During the months of March and April the mechanics and carpenters have been largely employed in preparations for the Eclipse. A considerable amount of work in wood and some in metal has been required to fit up two spectrographs and one long focus telescope.
The Report here presented refers to the year from 1927 May 11 to 1928 May 10, and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Thompson Dome, the covered passage and conservatory in the front court, the Central Store for publications and the sheds at the southern end of the Observatory was completed on November 5. The Astrographic Dome was recovered with papier-maché between November 4 and December 24. The room under the Shuckburgh Dome has been converted into a satisfactory chamber for the apparatus for the transmission of time signals to Rugby. Most of the structural alterations had been made at the date of the last report but the wiring and painting were completed later. The upper computing room is being improved by the introduction of a wooden partition separating it from the staircase leading to the Astrographic Dome.
At Abinger, the arrangements for water supply referred to in the last report were completed in July. Protection against frost was fitted to the supply pipes from the water-tower in February. The cylinders of one of the engines were taken to Chatham and overhauled at the end of March.
The Report here presented refers to the year from 1928 May 11 to 1929 May 10 and exhibits the state of the Observatory on the last-named day.
1. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the domes of the 28-inch and Sheepshanks Equatorials, the Altazimuth, Transit Pavilion and Photoheliograph was completed on July 14.
The weather vane on the Ball Mast was not moving freely and was dismounted and repaired in September. At the same time new wooden cross-trees were fitted to the top of the mast.
A small wooden building adjoining the Ball Turret is being erected on the roof of the Octagon Room to house a carbon arc and accessories required for observations of stellar temperatures being made with the 30-inch reflector. A new motor generator to supply direct current to this arc was received on March 27 and is being installed in the same room as the motor generator already in use. It will supply 20 amperes at 110 volts.
Provision of a motor to turn the 28-inch dome has been made in the Estimates.
At Abinger, lightning conductors were placed on the two Magnet Houses in November. The ignition of the engines has required some attention and repairs to the magnetos are being carried out. The exteriors of the buildings were painted in July.
The Report here presented refers to the year from 1929 May 11 to 1930 May 10, and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
The, external painting of the Thompson Dome, Octagon Room and Flamsteed House was completed on August 31.
The redecoration of the Upper and Lower Computing Rooms was completed on June 24.
The interior of the 28-inch dome was painted between February 6 and March 23 and some small repairs made of the papier-mâché covering. The exterior painting of the dome was finished on May 12, 1930. The contract for the motor to turn the dome has been placed.
A portion of the zinc work covering the Photoheliograph Dome was torn off during the gale of January 12. The necessary repairs were completed by February 21.
As the dark room adjoining the Thompson Dome is much exposed, it has been found to be too cold in the winter months for silvering mirrors and photographic purposes. Attempts to warm it by stoves have not been very successful, and a. shaft has been constructed to extend the hot air system into this room with satisfactory results.
The South Attic has been converted into an observing room for the Spectrohelioscope. This room also contains a Spectrophotometer, a small Spectrograph and an enlarging Camera. The book shelves which were originally in the room were moved into the West Attic and North Library.
On the return of the Eclipse instruments in July, an examination was made of the old instruments which had gradually accumulated at the Observatory. Amongst them were the following instruments of historical value: The Shuckburgh Equatorial, made by Ramsden, a fine early specimen of an English mounted equatorial; the Equatorial used by Admiral Smythe, the first clock-driven Telescope erected in England; Airy's Altazimuth. These instruments were presented by the Admiralty to the Science Museum, where they have been beautifully restored and are exhibited in the Astronomical Section. A mahogany tube of one of Herschel's reflectors, with the 6-inch speculum, was presented to a new astronomical museum at Chicago.
A considerable amount of material which was not worth preserving was handed over to the Naval Store Officer at West India Docks for disposal.
The electric generating plant at Abinger has given rise to some anxiety during the past twelve months. Detailed examination of the storage battery by inspectors from Chatham Dockyard revealed serious deterioration of the plates in a number of cells. The trouble has been met, temporarily, by measures taken to prevent further buckling of the plates in individual cells and the consequent liability to short circuits.
The generator engines were also found to be in need of a thorough overhaul. It was considered that the most practical way of dealing with this requirement was to replace them by duplicates. The substitution was carried out by engineers of the Chatham Dockyard staff during the first two weeks in February.
The Report here presented refers to the year from 1930 May 11 to 1931 May 10, and exhibits the state of the Observatory on the last-named day.
A generous offer to present a large telescope to the Observatory was made to me by Mr. William Johnston Yapp on March 13. After careful consideration it was decided that a 36-inch reflector would be the most useful addition to the equipment of the Observatory. To meet the cost of this instrument, with a spectroscope and a new 34-foot dome, Mr. Yapp has given £15,000. This munificent and public-spirited gift has been gratefully accepted by The Lords Commissioners of the Admiralty.
The new telescope will be devoted in the first place to spectroscopic observations of colour temperatures which have been carried on with some difficulty, as the 30-inch reflector is not separately mounted and not available when the 26-inch refractor is in use.
An order for the telescope and dome will be placed with Messrs. Sir Howard Grubb, Parsons &- Co.
I. – Buildings and Grounds, Movable Property, and Library:–
The external painting of the Astrographic, Sheepshanks, Altazimuth, Photoheliograph, and Transit Pavilion domes was completed on July 10, 1930.
The south vertical shutter of the transit circle room, which was in a bad condition, was removed and a new one fixed on July 10.
A considerable amount of redecoration and many small repairs have been carried out by the Works Department during the year.
The painting of the wall of the 28-inch dome after the installation of the motor referred to below, and the staircase to the dome, was completed in March.
The principal rooms in both storeys of the South Building as well as the central rooms and lobbies, and also the Workshop, have been repainted. The lead work on the turrets has been renewed. The painting in this building was completed in April.
The renewal of some of the wood-work and the external painting of the buildings in the courtyard of the Observatory is in progress at the date of this report.
The installation of a motor for turning the dome of the 28-inch Equatorial was completed in January. A three horse-power motor is carried on the dome, the current being supplied by contact pieces rubbing on insulated rails fixed to the walls of the building.
The large wireless aerial, stretching from the Octagon Room to the South Building, was taken down in October, as it was found no longer necessary.
At Abinger the positive plates of the main battery were renewed during August and
September. New wooden casing has been erected round the water-tower. A cement, flooring has been laid in the office where the wooden floor had suffered from dry rot.
A new steel silencer for the oil engines has been substituted for the brick one which was damaged by a small explosion.
The Report here presented refers to the year from 1931 May 11 to 1932 May 10, and exhibits the state of the Observatory on the last-named day.
I. – New Instruments :–
The new transit circle sanctioned by the Admiralty and the 36-inch Reflecting telescope presented by Mr. W. Johnstone Yapp will be erected in the grounds of the former Magnetic Observatory, with the approval of the Office of Works.
The buildings of the transit circle and Johnstone Yapp Equatorial have been designed by the Civil Engineer-in-Chief, in accordance with the requirements of the Astronomer Royal and of the Contractors for the instruments. Previous experience at the Cape Observatory has afforded useful guidance in the building for the transit circle.
An isolation trench 3 feet deep has been constructed around the transit circle to prevent moisture soaking through to the foundations of the instrument. The soil has proved to be extremely firm, so that the block of concrete for the foundation did not need to go below the depth of 9 feet. The base is 15 feet square, 3 feet thick, and surmounted by a block 12 feet by 9 feet with supporting struts.
The building above the axis of the instrument will be of semi-cylindrical form, and the opening will be 8 feet.
The collimators are at a distance of 50 feet from the centre of the instrument. The houses are nearly completed and are of sufficient size to allow of efficient ventilation.
The construction of the instrument is in the hands of Messrs. Cooke, Troughton and Simms, who have great experience in this kind of work. The instrument will be reversible … …
II. – Buildings and Grounds, Movable Property, and Library:–
The woodwork of the front court and the shutters of the transit circle were repainted during the year.
The room adjoining the Upper record room has been greatly improved by the removal of a large obstruction in the centre of the room which contained three disused chimney flues, and by the addition of a window in the roof. The room has been fitted up for the reception of wireless signals. The smaller room formerly used for this purpose has been repainted and converted into a store for stationery.
The small waiting room for visitors has been re-decorated.
The internal and external painting of the Thompson Dome was carried out during August and September, and the instrument was repainted at the same time. Opportunity was afforded by the scaffolding erected for the painters to renew the top rollers which carry the shutter of the dome. Gun metal rollers were substituted for the existing iron ones, which were much worn, with a considerable improvement in the running of the shutter.
At Abinger, a pavilion, 20 feet square, has been erected on the north side of the enclosure. This will be found very useful for the testing and standardisation of coil magnetometers and other magnetic instruments.
A concrete pillar, 10 feet in height, and distant 290 feet from the observing pier has been erected to carry an azimuth mark for the observations of declination.
The Report here presented refers to the year from 1932 May 11 to 1933 May 10, and exhibits the state of the Observatory on the last-named day.
Sir Frank Dyson retired from the office of Astronomer Royal on February 28. The observations referred to in the present Report were thus mostly made under his direction.
I. – New Instruments :–
The 36-inch Reflecting Telescope presented, with its accessories, by Mr. W. Johnston Yapp, which is being constructed by Messrs. Sir Howard Grubb, Parsons and Co., is practically completed. The two smaller quartz mirrors are finished and the 36-inch mirror is in its final stages. The instrument has been erected in the makers' works where tests on the optical and mechanical performance will be carried out.
A slitless spectrograph, to be used in conjunction with the 36-inch reflector, is under construction by Messrs. Adam Hilger, Ltd. Its design is modelled on that of the existing spectrograph attached to the 30-inch reflector. The construction is in an advanced state. The large prism is finished and the mechanical parts have been completed.
The building and dome for the reflector have been completed. The dome is rotated by means of an endless cable driven by an electric motor; it was tested on November 21 and found to be extremely satisfactory. The building was constructed by the Civil Engineer-in-Chief's Department of the Admiralty and the dome was constructed and erected by Messrs. Sir Howard Grubb, Parsons and Co.
The buildings for the new transit circle are being erected by the Civil Engineer-in-Chief's Department. The collimator houses have been finished and the foundations of the observing house are complete. Considerable progress is being made with the construction of the instrument by Messrs. Cooke, Troughton and Simms, Ltd.
A micrometer of the long-screw type, for measuring astrographic plates, has been purchased from Messrs. Adam Hilger, Ltd. The errors of the screw and slide have been investigated and are satisfactorily small. The instrument is convenient and accurate in use. It is being employed for the measurement of the photographs of Eros taken during the opposition of 1930-31.
II. – Buildings and Grounds, Movable Property, and Library:–
The exterior of the dome housing the 28-inch equatorial has been repainted as has also been the external woodwork of the South Building. A new entrance to the clock cellar, opening on the North Terrace, has been constructed.
The refrigerating plant, used in connection with the testing of chronometers, has been overhauled. An electrically-driven grinding machine has been installed in the workshop.
The voltage of the electrical supply to the enclosure containing the old Magnetic Observatory has been changed from 110 volts to 220 volts. This change has been made to meet the demands which will be created by the erection of the new reflector and transit circle. Conduit pipes have been run from the main Observatory to the enclosure, to carry the additional electric cables required for use with these instruments.
A new 110-volt transformer to supply current for power purposes in the South Building has been installed.
At Abinger, the engines for generating electrical supply have been overhauled. The following instruments which are in regular use have been lent to the Royal Observatory:
The Report here presented refers to the year from 1933 May 11 to 1934 May 10, and exhibits the state of the Observatory on the last-named day.
I. – New Instruments :–
The 36-inch Reflecting Telescope presented, with its accessories, by Mr. W. Johnston Yapp, has been completed and erected. The telescope and dome were constructed by Messrs. Sir Howard Grubb, Parsons and Co., and the building was erected by the Civil Engineer's Department of the Admiralty.
The mounting of the telescope is of the modified English form, that is the long polar axis is supported by piers at the north and south ends, the crosshead carrying the telescope being attached to the middle of the axis. The polar axis is long enough to permit of reversal under the axis. The telescope consists of a central heavy casting to which is attached, on the one side, the mirror cell, and on the other, the open work tube. The instrument can be turned by electric motors in either co-ordinate, quick and slow setting motions, in addition to guiding motions, being provided. The driving mechanism is of the Grubb pattern and incorporates important recent improvements by the makers.
Satisfactory progress has been made with the construction of the new transit circle by Messrs. Cooke, Troughton and Simms, Ltd. The mechanical work is approaching completion and the important stage of dividing the circles, which are of glass and of 28 inches diameter, has been reached. The housing for the instrument, constructed by the Cleveland Bridge Company, has been erected. The housing is semi-cylindrical in shape, the axis of the cylinder coinciding with that of tne transit circle, The interior diameter of the cylinder is 30 feet. Two shutters can be opened to give an aperture of 8 feet width along the meridian. The housing is covered externally with copper sheeting and adequate thermal insulation is secured by a lining of compressed cork slabs, 3 inches thick. The motor and gear for opening and closing the shutters have been installed.
A linear thermo-couple, by Messrs. Kipp and Zonen, and a Paschen galvanometer, by the Cambridge Scientific Instrument Company, have been purchased. They will be used for the measurement of total line intensities in the solar spectrum; the south gallery of the Altazimuth building is being used as an observing room.
A cathode ray oscillograph and mains unit has been purchased from Messrs. A. C. Cossor, Ltd. In conjunction with a motor-driven film camera giving continuous motion and a time marking oscillator, it will be employed for the accurate registration of radio time signals and for the determination of the time lag in the receiving apparatus. The oscillator was designed and constructed by the Radio Department of the National Physical Laboratory.
II. – Buildings and Grounds, Movable Property, and Library:–
A small building has been erected in the Enclosure containing the new transit circle building and the Yapp equatorial reflector. It forms an annexe to the Recording Room (formerly known as the Magnetograph House), and contains provision for the installation of the chronograph for recording the transit observations. Part of it will serve as an observers' rest room. The wooden structure in the enclosure, formerly known as the Magnetic Pavilion, has been demolished.
Various structural alterations were made to the interior of Flamsteed House consequent upon the change of occupancy; the house was also rewired and redecorated.
The cellar below Flamsteed House, adjacent to the existing clock cellar, has been prepared as a second clock cellar. The walls and ceiling have been rendered with cement, a new concrete floor and steps have been provided and a thick lagged door, to reduce leakage of heat, has been made.
The exteriors of several of the buildings, including the Octagonal Building and Flamsteed House, have been repainted. Internal re-decoration of the Transit Pavilion, Time Department Office, and Photoheliograph dome, has been carried out. The wooden staircase leading to the roof of the Octagonal Building has been repaired.
The Thompson Equatorial dome has been painted with aluminium paint. It is anticipated that this will prove more satisfactory than lead paint for the papier-mâché covered domes and that a longer interval will elapse before repainting becomes necessary.
The dome of the Transit Pavilion had become very difficult to open owing to the rusting of the iron work in places where it was impossible to keep it painted; this caused the angle iron to twist and resulted in considerable friction on the running rails. The two halves of the dome were therefore jacked up, the bad portions of ironwork were cut away and new angle iron pieces were bolted on.
Owing to a crack appearing in the stone on which the small reversible transit, used for time observations, is mounted, a new stone has been substituted. At the same time, the top portion of the brick work of the pier was rebuilt.
Lightning conductors, conforming to existing Admiralty regulations, have been fitted to the exteriors of all domes and buildings.
A new electric main cable has been laid between the basement housing the transformer and the courtyard. This cable is supplementary to the old cable and its installation was necessitated by the increase in the amount of electric current used for heating and power in the older portion of the Observatory. Electric heating has been installed in the Transit Pavilion and will be used in damp weather for keeping the small reversible transit and its accessories dry.
A new engraved "staybrite" [stainless steel] plate has been fixed outside the main entrance to the Observatory. It adjoins a flush bracket placed by the Ordnance Survey Department over an old bench mark cut on the wall, and gives the corresponding height above mean sea level at Newlyn (154.70 feet).
The pressure of the water supply having become unsatisfactory owing to deposits in the 6-inch main, the main was opened at several points and the deposit cleared. A satisfactory pressure is now obtained.
At Abinger the engines and main storage battery have been overhauled and minor internal decorations carried out to the dwelling house of the Assistant-in-Charge. The path from the entrance to the house has been made up and asphalted.
The Report here presented refers to the period from 1934 May 11 to 1935 April 30, and exhibits the state of the Observatory on the last-named day.
II. – Buildings and Grounds, Movable Property, and Library:–
The boundary fence on the east side of the Observatory, abutting on to the Main Avenue in Greenwich Park, has been renewed.
The air intake for the hot air heating system in the Main Building being in the stokehole, fumes and dirt from the stokehole were drawn through with the air and ejected into the rooms in the building. To obviate this, a new intake has been built, so that air from outside the building is drawn into the heating chamber. The opportunity was taken, whilst this work was in progress, to overhaul the system and to clean all flues and ducts. The alterations have greatly improved the conditions for the staff working in this building.
The pathway from the 28-inch dome to the Main Building has been re-laid with tar macadam.
The external painting with aluminium paint of the domes housing the following instruments has been completed: 28-inch refractor, altazimuth, Sheepshanks telescope, astrographic refractor, small transit instrument, and the 4-inch photoheliograph. All the painted domes have now been re-painted with aluminium paint.
The results are pleasing, and the appearance of the Observatory has been improved.
The interior re-decoration of the lower portion of the altazimuth building and the distempering of the walls of the building housing the 36-inch reflector have been completed. The floor of the basement of the latter building, which is being used for spectroscopic solar observations, has been covered with cork carpet.
A hut for housing the 16-inch coelostat has been built in the workshop and erected in the Christie Enclosure adjacent to the 36-inch reflector building, in connection with the solar observations.
The wiring of the new clock room, housing the two mean-time free pendulums, has been completed, and the necessary wires for connecting the two free pendulums with heir respective slave clocks in the Rugby Signal Room have been run. An additional length of cable was laid across the Courtyard for carrying the current for heating the clock cellar.
An additional telephone line from the Observatory to the local telephone exchange has been installed, to reduce the frequent delay in both outgoing and incoming calls.
The Report here presented refers to the period from 1935 May 1 to 1936 April 30 and exhibits the state of the Observatory on the last-named day.
II. – Buildings and Grounds, Movable Property, and Library:–
A new building for housing the Cookson zenith telescope has been erected in the Christie Enclosure adjacent to the south collimator house of the reversible transit. The central section of the roof is mounted on wheels, running on rails. This section can be opened or closed by turning a handle inside the building, which, through bevel gearing and appropriate shafting, turns sprocket wheels on the north and south sides of the building. These wheels engage in roller chains, whose ends are attached to the movable portion of the roof. The wiring of the building is now in progress.
Paths have been laid in the Christie Enclosure between the several buildings and the gateway.
Consequent upon the alterations to the 26-inch refractor, described on p.12, the greater portion of the gallery and the false floor surrounding the base of the instrument have been removed. The whole of the electrical circuits in the dome and the adjacent dark rooms have been rewired and internal decorations have been carried out.
A survey of the photoheliograph dome showed that it was in a dangerous condition. The covering of the dome was therefore stripped off, new wooden formers were made and fitted and covered with new zinc panels.
A fluctuation in the general lighting in the observatory which occurred at the times when the compressor, for the refrigerating plant of the chronometer testing cold chamber, was in operation, proved very troublesome when any of the measuring machines or the photometer were in use. To eliminate this fluctuation, an independent 220-volt transformer was installed to supply the Brook's main. This has proved to be satisfactory.
The greater portion of the boundary fence on the west side of the Observatory has been renewed.
A new sectional boiler has been installed, for heating the chronometer store, wireless room and record room.
The dome housing the 26-inch refractor has been repainted externally with aluminium paint.
The external painting of the following buildings has been completed: South-east building and covered way, New Store, Altazimuth, Porter's Lodge. The water tower at the Magnetic Observatory, Abinger, has been repainted.
The internal redecorations of the following portions of the Observatory have been completed: the Octagon Room, Ball Lobby and Staircase, the Transit Circle Room, Chronograph Room, passage leading to Time Department, Porter's Lodge, Magnetograph Building in Christie Enclosure. At the Magnetic Observatory, Abinger, the garage, store, engine and battery rooms, the magnetic pavilion, old testing hut and portions of the Assistant's and Caretaker's quarters have been redecorated.
A fence has been erected along the north boundary of the Magnetic Observatory Abinger.
The main battery at Abinger has been overhauled and sludge removed. All pendant wiring has been renewed.
The Report here presented refers to the period from 1936 May 1 to 1937 April 30 and exhibits the state of the Observatory on the last-named day.
The Nautical Almanac Office has been placed under the direction of the Astronomer Royal and has been made a branch of the Royal Observatory. The Superintendent of the Office has been given the status of a Chief Assistant in the Royal Observatory. It is of interest to recall that the Nautical Almanac originated with Maskelyne, the first volume appearing in 1765, the year following his appointment as Astronomer Royal. He carried it on until his death in 1811, the almanacs for the years 1767 to 1816 inclusive having been produced under his direction. The Royal Observatory was founded, in 1675, "for perfecting navigation and astronomy." The Nautical Almanac, in the abridged and standard editions, caters for the needs both of the navigator and of the astronomer. It is appropriate, therefore, that it should again be produced, as it was initially, by the Royal Observatory.
II. – Buildings and Grounds, Movable Property, and Library:–
With the increased junior staff at the Nautical Almanac Office and the proposals for the general increase of permanent and temporary staff to provide for the additional annual and temporary work recently undertaken for the Admiralty and the Air Ministry, further accommodation became essential. In October, the Admiral President of the Royal Naval College placed three additional rooms at the disposal of the Office, which were immediately furnished and put into use ; pending the final decision as to the complement required for the extra work, consideration of the question of the future permanent accommodation of the Office has been deferred.
The extra accommodation made possible the redistribution of the staff, with the almost complete separation of mechanical and non-mechanical work, and has also allowed more space for the display of the books in the Nautical Almanac Office library. A card catalogue of these books, which has been urgently desired for many years and has now been made possible, is in preparation.
Louvred partitions have been erected in the East Wing of the Main Building of the Observatory. A projection micrometer and microphotometer are installed in the portion of the room thus screened off.
Part of the Upper Computing Room has been screened by partitions and will be used as a watch and chronometer repairing workshop.
The boundary fence on the west side of the Observatory has now been completely renewed.
The external painting of the following buildings and domes has been completed: Main Building, New Store, Thermograph Hut, iron work of Yapp Dome and Reversible Transit Circle Pavilion, S.E. Dome, Sheepshanks Dome, Altazimuth Dome, Photoheliograph Dome, Shuckburg[h] Dome and Small Transit Pavilion. In the Main Building, the lighting circuits in the Libraries, Workshop, Lower Museum and Staircase have been rewired, and lighting has been installed in the east and west attics. New electric light fittings have been installed in the. Octagon Room.
The hut housing the Robinson Anemometer has been rebuilt.
In the Christie Enclosure a new 3-inch fire hydrant has been installed and
portable extinguishers provided at various points. An electric cable has been laid from the feeder pillar to the new Cookson building.
New doors have been fitted to the old offices and the building repainted. A new store cupboard has been erected outside the new clock room. A portion of the new Cookson building has been screened off and converted into a small dark room for loading plate carriers.
At the Abinger Magnetic Station a small wooden house has been erected for housing the 50-volt battery used in coil magnetometer observations. A water main has been laid to the dark room. The office and residences have been painted externally. A lavatory has been added to the office buildings. The sewerage system has been reconstructed. Work is proceeding in connection with the change of electric supply, which since March 11 has been taken from the new local mains.
The Report here presented refers to the period from 1937 May 1 to 1938 April 30 and exhibits the state of the Observatory on the last-named day.
II. – Buildings and Grounds, Movable Property, and Library:–
The four conduit rails for the 28-inch dome motor have been removed, together with the contact arms, and a flexible lead has been run from the main girder at the apex of the dome to the top of the north pier and so to the controls. This arrangement is possible since the telescope cannot in any case cross the meridian except well south of the zenith. By this means the maximum travel of the dome has been increased from 180° to about 310°. External painting of the dome will in future require only one scaffold and it is hoped in consequence to reduce appreciably the cost of the biennial painting. The mechanism for operating the dome shutters, which had worn out, has been replaced by an endless steel cable and winch operated at the side of the dome; the work was designed and carried out by the workshop staff, and the gain in convenience is appreciable.
The water-clock formerly used for driving the 28-inch refractor has been removed and presented to the Science Museum, together with Airy's Water Telescope and Reflex Zenith Tube.
The shutters of the Airy, Transit Circle have been covered with copper sheeting.
The old battery basement has been converted into a thermostatically-controlled room for the new crystal clock. A large capacity battery has been obtained from surplus stock at the National Physical Laboratory and work is in progress on a new battery room for it. The battery will be able to drive a small 220 volt A.C. motor generator in case of mains failure, so as to keep the crystal clock in operation and also hold the temperature of its cabinet constant for a limited period.
The adaptation of the old battery basement necessitated the transference of part of the apparatus for lifting the time ball to the ball lobby; at the same time, a new braking system was arranged, as well as an indicator to show the position of the ball. The coils of the electro-magnets in the release apparatus have been rewired.
The old watch room has been converted into a computing room for the use of the time department. The new watch room is now complete; cupboards for storing watch boxes have been fitted, and extra heating and lighting have been provided.
The charging panel for small batteries has been removed from the wireless room and installed in a small cupboard near the time battery room. A new 7-pair cable has been laid from the lower computing room to the wireless room.
The lead flats on the roof of the Octagon room have been overhauled and repaired where necessary and the flagstaff moved from the west to the east side of the building, so that it is no longer possible for the flag to foul the anemometer cups.
The Chart room has been converted into a rest room for the female staff. Heating for this room, and also for the Thompson dark room, has been arranged by diverting part of the hot air duct.
An Ascot water heater has been installed in the lavatory on the principal floor of the Main Building.
A small dark cupboard has been erected in the Thompson dome for loading and changing plates.
A set of bookshelves has been constructed and fitted in the Astronomer Royal's office.
The tables removed from the old watch room have been erected in the east attic and adapted for mounting an optical bench.
The floor of the old magnetograph house in the Christie Enclosure has been re-rendered with cement.
Louvred frames, painted white, have been fitted on the roof and the south and west sides of the Cookson building. It was found that on warm sunny days the roof and the south and west walls became heated, causing temperature gradients in the hut from north to south and from east to west, which would have produced apparent displacements of the zenith. The louvred frames have successfully eliminated these temperature gradients.
The floor of the solar dark room has been re-covered with sheet lead, the woodwork under the sink has been repaired and the room has been redecorated.
The floors of the Cookson building, photoheliograph dome, chronograph room and new watch room have been covered with corticene.
New gates have been fitted at the main entrance to the Observatory.
The necessary equipment for the 3-inch fire hydrant in the Christie enclosure, mentioned in the report last year, has now been supplied.
All fuse boxes with fuses of obsolete pattern have been replaced by boxes with standard type fuses.
The external painting of the following buildings and domes has been completed:-
Octagon room, north and east sides of Flamsteed House, north side of Old Observatory, covered way, Central Store and 26-inch dome.
The interior painting of the Yapp dome (walls only), silvering room, watch rating room and paper store has been completed.
At the Abinger Magnetic Station the mains supply of electricity has been extended to all buildings. Heating elements similar to those in use in the magnetograph chamber have been provided in the pavilion for absolute observations and in the two testing huts. An automatic electric fire-alarm system has been installed in each of the buildings in the magnetic enclosure.
The interior of the magnetograph house, including the recording chamber, has been re-painted.
The Report here presented refers to the period from 1938 May I to 1939 April 30 and exhibits the state of the Observatory on the last-named day.
II. – Buildings and Grounds, Movable Property, and Library:–
The winch and gear bracket employed in the new shutter mechanism for the
28-inch dome was adapted from an old casting. It proved unequal to the treatment it received during repainting of the dome, and the construction of a new bracket was shared between the Observatory and the Royal Victoria Yard, Deptford. The drawing and pattern-making was done in the workshop, and the casting and machining at Deptford. The dome was out of action from June 27 to September 19, during which time, however, it was painted inside and out.
Shortly after work with the 28-inch had been resumed, the dome rail fractured. Examination showed that not only had one large piece broken away, but also there were a number of other minor breakages and danger spots. In fact it was recognised that the rail was nearly worn out. Its replacement would, however, be expensive, since it is a special casting integral with the rack for the dome-revolving mechanism. It was therefore decided to repair the fractures by welding, as a temporary measure. The dome was out of action on this occasion from November 8 to November 19. On April 10 a further fracture occurred. There is no doubt that the condition of the wheels is in large measure responsible for these fractures. The wheels are of cast iron, rather narrow, and they have worn a groove in the rail. When they ride up the side of this groove, the load comes on the edge of the wheels, and causes them to chip. Large chips have been detached from all ten wheels in this way, and if a wheel subsequently rides over such a chip the load is very high locally; there may also be a severe bump. Various firms are being consulted as to the best procedure, and it is possible that by turning the wheels down and fitting steel treads, rounded more or less to suit the groove in the rail, a fairly safe temporary solution may be found, provided that the rail can be repaired again. The previous welding was done with oxygen, and the contraction on cooling has resulted in a crack in the main web of the rail. Electric welding would be safer in this respect, but is less homogeneous. There is no doubt that really adequate proposals would have to be much more radical. At present the telescope is not entirely out of action; the dome has been placed in a position that allows a selection of stars to be observed without moving it, provided conditions are suitable for the star in question at the time required.
In Flamsteed House the larder has been converted for the accommodation of batteries for the regular time service and also of the high-capacity cells required to provide current for the crystal clock in the event of an interruption of the mains supply. A partition has been erected in the laundry to form a new larder, which has been fitted with shelves and new lighting points. A new domestic boiler has been installed in the kitchen, and the floor of the laundry has been relaid with wood blocks.
About 60 feet of 2-inch main gas piping has been renewed in the courtyard. New wires have been laid in conduits to the Rugby room, new battery room, and small transit pavilion. The courtyard has been surfaced with tar macadam.
A portion of the flooring and joists in the lower computing room has been replaced with concrete. Parts of the cornice surrounding the photoheliograph dome have been removed, pending repairs, as their condition was dangerous. Minor alterations to the benches in the watch-repairing room have been undertaken, and the floor has been covered with corticene. Portable two-tier shelves have been made, that can be added to the tables in the upper chronometer room when the number of watches being tested is exceptional.
In the main building, structural alterations have been carried out on the museum floor so as to add to the size of the Secretary's Office. The lighting system in the south wing has been rewired. The accommodation in the ladies' lavatory has been increased, a wash basin and Ascot heater have been added, and a separate entrance to the adjoining photographic dark room has been constructed. Work on the ladies' room in the old building has been postponed until completion of the new battery room. New cupboards for storing parallax plates have been made, and also one for the spares of the Reversible Transit Circle. A table has been made for apparatus at Abinger, and a long table has been altered to serve as a foundation for optical benches, etc., in the laboratory. The windows in the Astronomer Royal's Office have been fitted with draught-proof sashes.
Following on the improvement produced in the Cookson results by erecting louvre screens on the south and west of the building, the roofs and south and west sides of the two collimator houses were similarly treated. Determinations of collimation are still usually difficult, but the conditions soon after sunset on fine days are better than they were.
At Abinger a wood block floor has been laid in the old testing hut and a new motor has been fitted to the fresh-water pump. The old main battery has been dismantled. A pier has been built for a small transit instrument to be used for the determination of time.
The following painting work was done during the year:-
Exteriors: Sheepshanks Dome, Altazimuth Dome, Yapp building, steel work on Reversible Transit Circle Dome, Collimator houses, Magnetograph house and annex, 28-inch Dome, railings on north boundary, boxes containing fire apparatus, main gates. At Abinger, the magnet houses.
Interiors: 28-inch Dome, staircase and lower landing, upper and lower Chronometer Rooms, ceiling of Watch Repairing Room, new partition and part of wall on museum floor of main building. At Abinger, some decorating of the Caretaker’s quarters.
The Report here presented refers to the period from 1939 May I to 1940 April 30 and exhibits the state of the Observatory on the last-named day.
II. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
The section of the track rail of the 28-inch dome, which was fractured early in 1939, has been successfully repaired by electrical welding. This is a temporary expedient and further trouble is to be expected unless both the track and the dome wheels are renewed. The proposals that were under consideration for the removal of the Observatory to a new site made it inadvisable t o incur this heavy expense. Meanwhile, as the telescope is not at present in use, the question whether more extensive repairs should be undertaken has remained in abeyance.
The new 4-inch water main leading from the Main Avenue to the Christie Enclosure has been completed.
The Altazimuth Instrument has been dismantled and stored. A brick pier has been erected in the dome to take the Cooke Small Transit Instrument.
The windows of the ground floor of the South-East Dome and of the Lower Chronometer Store have been bricked up. A concrete housing for the new time desk and terminal frame was erected on the site of the cold greenhouse; a new greenhouse has been erected adjoining this room.
The ceiling of the Central Store, which was found to be in a dangerous condition, has been taken down and is being replaced by plaster board.
New fireplaces have been fitted in the West Wing of the Main Building and in the Low Computing Room.
A new wash basin has been fitted in the workmen's lavatory; and a new wash basin has been fitted in the lavatory outside the Lower Computing Room.
A concrete cable trench for new time circuits has been laid through the Time Department, the Airy Transit Circle house and the passage.
Dark blinds have been fitted to the windows throughout the Observatory.
At Abinger, a wooden housing for the small transit instrument has been erected. Special care was taken in the design of this building to secure adequate ventilation and to avoid stratification of the air. A portion of the old battery room has been divided off by insulated plaster board for use as a clock room and thermostatically controlled electric heating has been installed. The former engine room has been divided off by glazed partitions and a block flooring has been laid.
A considerable amount of time has been spent on Passive Defence Work. The 28-inch and 26-inch object glasses have been dismounted and removed to a place of safety. Steps have been taken to protect the Flamsteed manuscripts and other valuable books and records. Suitable refuges for the staff have been prepared.
The following painting was done during the year:
Internal redecoration of the South, East and West Wings, South Lobby, Workshop, Workmen's Lavatory and First Aid Room in the Main Building; the Altazimuth Dome and walls; the Upper Computing Room and the Lower Chronometer Store. In Flamsteed House, five bedrooms and bathroom. At Abinger, the house of the Assistant-in-Charge was redecorated internally and externally on change of occupancy, and the water tower was repainted.
The Report here presented refers to the period from 1940 May I to 1941 April 30 and exhibits the state of the Observatory on the last-named day.
I. Buildings and Grounds, Movable Property, and Library:–
The buildings have received damage on several occasions by enemy action, The north wing of the Main Building and the south portico of the Altazimuth building have both received direct hits from bombs; the damage, though considerable is not serious. The main gates and supporting pillars have been destroyed by a direct hit, when most of the covered way in the courtyard was also destroyed. There has been extensive damage to windows, window frames and ceilings throughout the Observatory. The coverings of the altazimuth and transit pavilion domes have been destroyed and those of the 28-inch refractor and 26-inch refractor domes have been riddled with holes by fragments. The Cooke small transit instrument was broken in half when thrown from its mounting in the altazimuth domes though the object glass was undamaged. The Cookson telescope received minor damage when the exposing shutter above the instrument was detached by blast and dropped on the telescope. The large lenses, mirrors, and some other valuable parts of the principal instruments have been sent away from Greenwich for safety. No structural repairs to damaged buildings have been made, but temporary repairs have boon carried out.
A new personal equation machine has been constructed in the Observatory Workshop and fitted to the South Collimator on the Altazimuth Dome,
The brick pier for mounting the Cooke Small Transit Instrument, mentioned in the report last year, has been erected. This is surrounded by wood panelling, to which an electrical control panel has been fixed; this serves all the wiring circuits for the Instrument, Personal Equation machine and Chronograph.
The power and lighting circuits have been rewired in the Dome and a main switch arranged at the south entrance.
Patterns have been made for casting the metal base and parts for the variometer now in use at the Magnetic Station, Abinger.
New castings have been fitted as toe plates to the strider level and a new bubble fitted for use with the Small Transit Instruments.
Two of three two-pen chronographs have been constructed in the Workshops. These chronographs are fitted with synchronous induction motors for conveying the tape at a uniform speed. The third chronograph is now under constructions, together with portable double spring gramophone motor as an alternative for conveying the tape on either machine.
A new relay control panel for the clock circuits and chronograph has been completed for use at one of the emergency time stations.
The following painting was done during the year:
External painting of all the domes in the Observatory grounds Stevenson’s screens; thermometer stands, and the metal work of the Cookson shutter.
All the teak doors of the buildings in the Christie Enclosure have been revarnished.
A new section together with new fire doors have been fitted to the independent boiler for central heating of the Wren building.
The new drilling machine was received in August.
Addendum to Report
Buildings. Damage to the buildings at Greenwich was caused by direct hits from H.E. bombs on the nights of 1940 October 15–16 and October 21–22. Superficial damage in a varying degree was caused by blast from H.E. bombs falling near the Observatory on the nights of 1940 October 19–20, December 8–9, 1941 March 19–20 and by the explosion of a delayed action bomb on March 28. Minor damage has been caused by blast on several other occasions. Incendiary bombs fell within the Observatory grounds on the nights of 1940 December 27–28, 1941 March 19–20, April 19–20 and May 10–11. These were on each occasion dealt with by the A.R.P. squad on duty at the Observatory: the only damage caused by them has been to the fencing of the Christie Enclosure.
When it became necessary to terminate night observations at Greenwich and to operate the time service from the Magnetic Observatory at Abinger (Station A of the Report), the house “Cornerways”, Abinger Hammer, was taken for the Office staff and for the staffs of the Time and other Departments, which were moved from Greenwich.
The premises of 124, Pembroke Road, Clifton, Bristol, taken as Chronometer Depot at the beginning of the war, have been given up. New premises have been taken at “Lynchetts”, Woolley Street, Bradford-on-Avon.
The Report here presented refers to the period from 1941 May 1 to 1942 April 30 and exhibits the state of the Observatory on the last-named day.
I. – Buildings and Grounds, Movable Property, and Library:–
A building has been erected at Time station A to provide suitable and adequate housing for three Shortt free-pendulum clocks and for the quartz clock, with a minimum of expense and labour. It consists of two separate clock chambers, inside a main brick and concrete room, approximately 25 square feet in area. The outer room is heated by hot-water radiators, the clock chambers being electrically heated, with thermostatic control. The slave clocks and ancillary equipment will be installed in n the outer room. Progress on the building, which has now been completed, was slow; the installation of the necessary wiring, preparatory to the erection of the standard clocks, is in hand.
No further damage from enemy action was sustained during the year. No structural repairs to the war damage have been effected but the temporary repairs, made to prevent the deterioration of buildings and domes, have in some cases been improved upon, A wooden framework covered with felting, has been erected to close the large gap over the south portico of the altazimuth building and a similar construction is being provided for the north attic of the main Building. Further repairs have been made to the shutters of the Airy Transit Circle room, to render them usable for transit observations. The ceilings of the transit and chronograph rooms have been repaired. Improvements to daylight lighting of some of the offices have been effected by use of Luxoid glass substitute. Gaps in the fence of the Christie enclosure have been closed with barbed wire.
All instruments, which are not in use, have been protected from deterioration by the use, where necessary, of rust proofing oil and grease. The pivots Of the Reversible Transit Instrument were carefully examined six months after such protection and were found to he in perfect condition. All instruments have been examined at regular intervals.
The dome rotor of the 26-inch refractor, which had been under repair, has been re-erected.
The drilling machine and circular saw, with morticing attachment, have been fixed in position in the workshop and wired for power.
A 5,000 gallon water tank has been erected in the Observatory courtyard.
The third two p-pen chronograph, mentioned in last year's report, has been completed in the workshop. A vibration machine, for testing the rates of aircraft watches under vibrations similar to those to which they are subjected in aircraft, has been constructed in the workshop.
Contacts of the Ritchie type have been made and fitted to the Dent mean time clock. The Dent sidereal clock is being fitted with similar contacts.
The Report here presented refers to the period from 1942 May 1 to 1943 April 30 and exhibits the state of the Observatory on the last named day.
I. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
No further damage from enemy action was sustained during the year. Temporary repairs effected since 1940 have been kept in good order. The lower framework and the running track of the Yapp dome have been repainted. A new door has been fitted at the top of the internal staircase giving access to the roof of the Octagon Room. The radiators in Flamsteed House and the Octagon Room have been repaired, and one has been replaced. All power and lighting circuits have been overhauled and tested. The West and North Libraries have been thoroughly cleaned and each book has been inspected and, where necessary, re-labelled.
All instruments which are not in use at the present time have been examined at regular intervals; the protection against rust by special oil and grease has been renewed where necessary. A demagnetising coil with rheostat for demagnetising watches has been designed and constructed in the Observatory workshop; it has been installed at the Chronometer Depot, where it has proved very effective in use.
The Report here presented refers to the period from 1943 May 1 to 1944 April 30 and exhibits the state of the Observatory on the last named day.
I. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
No further damage by enemy action has been sustained during the year. Plate glass is being restored to windows broken in 1940, belonging to parts of the Main Building. The Ball Lobby has been redistempered and cleaned and woodwork on the roof of the Octagon Room coated with preservative. Re-labelling of books in the Library has been continued throughout the year. A regular inspection of instruments the use of which is temporarily discontinued has been made and steps taken where necessary to preserve their condition,
A new workshop was erected at Station A in October to cope with the increased demand for constructional work and apparatus needed by the Time Department.
Enlargement of the accommodation needed for the Time Department at Station A has continued throughout the year. One building equipped for use as a laboratory and for temporary office accommodation has been completed and put into use, and the construction of a second building to contain clock cellars, for the new quartz clock equipment, and permanent office accommodation, has been approved. It is now in course of erection and completion within the next few months is anticipated.
A bench grinder has been added to the equipment at Station A and a portable high speed drill with flexible drive has been constructed in the workshop.
One of the two-pen chronographs, constructed in the workshop, has been converted to give double speed, making the scale 100 mm, per sec.
Various mains units and chassis with component parts for rack mounting have been constructed in the workshop as equipment for the Time Department.
The Report here presented refers to the period from 1944 May 1 to 1945 April 30 and exhibits the state of the Observatory on the last named day.
I. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
On July 15, a flying bomb exploded in Greenwich Park not far from the building of the 28-inch Refractor. Widespread damage, fortunately mainly, of a superficial nature, was thereby caused to domes, doors, windows and frames, ceilings and fences. Much of the existing first-aid repair work in several parts of the Observatory was damaged. The dome covering of the 28-inch refractor was stripped to a considerable extent. The Thompson Dome suffered less severely in this way. None of the instruments was damaged. The Chief Civil Engineer of the Admiralty (Thames) and the Civil Engineer, Royal Victoria Dock Yard, Deptford, visited the Observatory on 17 July in connection with this incident.
Minor damage from blast occurred on three or four other occasions.
Early in March, under the direction of the Civil Engineer, Royal Victoria Yard, Deptford, tubular steel scaffolding was erected inside the octagon Room to support the panelling which had been strained and displaced by accumulative effects of blast. The scaffolding was arranged so as to preserve as far as possible the cornice and ceiling of the Octagon Room, should parts become dislodged.
The erection at the Chronometer Depot, Bradford-on-Avon of a prefabricated building to house the watch repair shop was, after some delay, completed at the end of December and the transfer of the work from the main building was completed by mid-January. The building has 54 feet of benches with good north lighting, bench space for lathes, cleaning machines and watch rate-recorders whilst benches along the south side of the building provide accommodation for rating and jobs additional to the normal repair work.
The old telephone cable from the Porter's Lodge to the Main Building was replaced by a new one in August.
On April 13 a bench mark was fixed on the leaded roof of the Octagon Room as a reference point in triangulation work being carried out by the Ordnance Survey.
The Report here presented refers to the period from 1945 May 1 to 1946 April 30 and exhibits the state of the Observatory on the last named day.
I. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
New piers and gates have been erected at the Main Entrance to replace the temporary structure built when the original gates were destroyed in 1941.
The Shepherd 24-hour clock and the public barometer, near the Main Entrance, were considerably damaged when the Entrance was destroyed. As both of these were always of great interest to the public, repairs have been undertaken. The public barometer has been reinstated; the repairs to the 24-hour clock have been completed, but the clock is awaiting a new dial.
The dome of the Altazimuth Pavilion has been recovered and painted preparatory to repairs to the building itself.
The covering of the dome of the 28-inch equatorial, which was seriously damaged by blast on several occasions, is beyond repair. In view of the pending removal of the Observatory from Greenwich, the covering will not be renewed. When storage accommodation is available, it is proposed to dismantle the instrument and to store it, pending re-erection on the new site, in order to prevent deterioration of the telescope and mounting.
General repair work on a limited scale has been carried out, where necessary, to doors, window-frames and other minor fittings, but no attempt has yet been made to commence any structural repairs.
A portion of Flamsteed House was repaired sufficiently to enable the Astronomer Royal to resume occupation on October 1.
A new telephone switchboard has been installed in the Lodge.
A Nissen hut to serve as a temporary workshop for the Time Department, a small brick building to house a Diesel generating set and a temporary garage for Service vehicles have been erected at the Abinger Magnetic Station.
The Report here presented refers to the period from 1946 May 1 to 1947 April 30 and exhibits the state of the Observatory on the last named day.
I. BUILDINGS, GROUNDS, MOVABLE PROPERTY AND LIBRARY.
War damage repairs have continued throughout the year but are still confined to items essential to performance of work or to prevent further deterioration. They include the Central Store, Porters Lodge, south boundary fence and Rugby Clock room. The south portico of the Altazimuth Dome is being rebuilt and the damaged shutter of the collimator repaired. Repairs to the north boundary fence are now in progress.
A very limited amount of interior and exterior decoration has been done.
A new dial for the Shepherd 24-hour clock near the main entrance has been supplied by Messrs. James Cooke and Son, of Stechford, Birmingham. An exact copy has been made of the original dial, which was damaged when the entrance was destroyed during the war; the makers of the dial have generously presented it to the Royal Observatory without any charge.
At the Abinger Magnetic Station the entrance roadway has been resurfaced with concrete, the gateway has been widened, and the drive has been resurfaced with tarmac. The entrance gates and adjacent fencing, which were damaged by the fall, during a heavy gale, of two large beech trees near the entrance, have been replaced.
The rooms at the Magnetic Station, originally used to house batteries and engines and subsequently for time service equipment, have been converted for use as dark rooms. The fittings, including wet and dry benches, were designed by the Admiralty Photographic and Instrument Research Laboratory and were made by the Construction Department, H. M. Dockyard, Chatham.
For the better reception of foreign time signals, 98-ft. Adastra masts have been erected on Wotton Common. One of the masts, which received damage during a heavy gale, has been repaired.
The roofs of the two small transit huts at Abinger were damaged by the winter gales. The roof of one hut received further damage after repairs had been completed and is now awaiting repair.
Modifications are in progress to the electrical supply installation at Abinger. A new cable has been laid across the courtyard between the diesel-generator house and the main switchboard. The supply cable is overloaded and the installation of a new cable is under consideration.
The Report here presented refers to the period from 1947 may 1 to 1948 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
(a) Greenwich. War damage repairs to the Altazimuth Building know serving a Small Transit Pavilion) have been completed, and a new roof has been placed over the Upper Record Room. Boundary fences of the main and Christie enclosures have been repaired, The old Upper Computing Room has been made into a Control Room for the six quartz clocks; it has been Provided with a new ceiling and re-decorated, as has the old Wireless Roam, The Anemometer huts and Ball Turret on the roof of the Wren Building, and the porter’s have been re-painted, and some external painting has been done, where urgently necessary on the Yapp dome, R.T.C. Pavilions Vinery, and Stevenson screens. There is still a good deal of glass to be replaced in the Main Building, particularly in the West Library, where the books are suffering from dirt and damp, and some structural damage has yet to be repaired. Glass is also required for the octagon Room, and blast damage is still outstanding there and elsewhere. The 28-inch and 26-inch domes, both of which are now empty and neither of which is probably suitable for transfer to Herstmonceux, are in a bad state of repair and very unsightly; pending a final decision on their fate, no work on them has been undertaken.
(b) Abinger, A new sliding shutter has been fitted to the roof of the Bamberg transit bat. A number of dangerous trees in the immediate vicinity of the buildings or bordering on public footpaths have been felled. The lavatory facilities have been extended, and minor works of repair and maintenance carried out. Fluorescent lighting has been installed throughout the offices, laboratories, workshop and control room.
Admiralty approval has been given for acquiring the tenancy of a private house in tho district for use as offices, stores, hostel and canteen, and to provide accommodation for some married staff.
(c) Herstmonceux. Conversion work in the Castle and huts is proceeding, and it is expected that "Stage I" of the move will take place in August, except for the Solar Department, which will follow after a few months more. Some of the huts are already in use as a hostel for Dockyard and other workmen, canteen staff, etc., and the remainder are nearly ready for furnishing. The chronometer workshop in one of the huts is well advanced, and the Astronomer Royal's residence in the Castle is approaching completion. N Nautical Almanac quarters, in the brick huts, still require a fair amount of works but it is expected that they will be ready in time. Work on the chronometer rating rooms, m the Castle, has had to be postponed, because of alterations required in the Great Hall, immediately above them; the Hall is to serve as the Observatory Library, and it will be necessary to reconstruct the floor with steel supports before it can sustain the weight of books involved. A gallery is to be built along one side of the Great Hall, to carry additional book-stacks. As an interim measure for Stage I, some rooms on the upper floor arc being converted into temporary chronometer rating roams. The road from the West Lodge to the Castle and the huts has been repaired and coated with tarmac.
A start has also been made with the Solar Building; the access road to it is partly constructed and the foundations of the building itself have been laid. The Newbegin dome will be erected on this building, and will house the Newbegin refractor with the 4' photoheliograph attached to it. The telescope itself will be used for occultations, and also for instruction of junior staff, demonstrations, and miscellaneous tasks. The building, which was designed in the observatory, provides also for both the Greenwich and Newbegin Spectrohelioscopes, and for the 3½- prism Littrow spectrograph. It contains a darkroom, a small workshop, and an office and workroom arranged to accommodate a measuring machine. The main office work of the Department will be carried on in the castle, but provision is made for work in the new building also, so that time spent waiting for clear skies on doubtful days need not be wasted. It is planned to mount a Shortt master pendulum on the main pier; although this will not be thermostatically controlled, it will serve to carry the time between radio signals, and it will in fact be the nearest approach to a precision standard at Herstmonceux for years.
It is proposed to construct a cellar just outside the building on the east side. This is intended for a spectroheliograph employing large glass prisms and a spectrograph with large liquid prisms; both of these require steady temperature conditions,,
A general outline of the proposals for buildings to follow Stage I was submitted at the end of October, so that full estimates of the total cost of the move could be prepared. This work has taken some time, and no further appropriation, beyond the unexpended balance of what had already been voted for Stage I, was made in the Estimates for 1948-49. The difficulties which may result are discussed in Section XI.
It has already been mentioned that "Stage I" of the Herstmonceux move is planned to take place in August. This is intended to include the Nautical Almanac Office, the Chronometer Depot, the Magnetic and Meteorological Department and the Secretariat; the Astronomer Royal will probably transfer his residence somewhat earlier, and the Solar Department will wait until the Solar Building (but not the cellar is ready. At present no date for any further stage of the move can even be guessed at, and indeed the completion of Stage I cannot in fact at present be guaranteed.
The removal of the Royal Observatory from Greenwich to Herstmonceux would even under normal conditions have entailed considerable disorganization to the work of the Observatory. The difficulties of the present times, by delaying the completion of the move, will greatly increase this disorganization. It is hoped that some further funds will be forthcoming to allow Stage I to be completed; but there is no provision in the estimates for the current financial year for further stage of the work to be commenced. It would be wasteful to disband the present force of workmen with so much still to be done; but even more regrettable is, the effect on the output of the Observatory of each month of delay in completing the move. The 26-inch and 28-inch refractors and the Melbourne transit circle, are out of action; the completion of the Photographic Zenith Tube may be expected before long. Buildings to house these instruments are required. At Greenwich the Yapp reflector as already explained, is handicapped in that, it cannot profitably be re-aluminised as long as it remains there, while latitude variation observations are in abeyance because the resumption of observations with the Cookson telescope for a short period is not advisable. The Photographic Zenith Tube, when installed at Herstmonceux, will provide both time and latitude variation.
The actual output of the Observatory is thus much reduced at present; and, apart from this, the situation which will hold from the end of Stage I until completion the move will be gravely disadvantageous in other ways. The Observatory will be divided between Greenwich, Abinger and Herstmonceux, so that only one of the three branches .will have ready access to the Library, and the facilities of the Workshop will also be available only in: a very limited and unsatisfactory degree; this will be true; no matter when the Library and Workshop themselves actually move. Most serious of all, though least obvious in its effects, is the fact that both Herstmonceux and (still more) Abinger will have a marked excess of observers over instruments; already many valuable years of what should have been training have been lost, older observers are retiring, and new staff who have never made an observation are increasing. Even if the dismemberment of the Observatory could be terminated tomorrow, there would be, a large amount of ground to make up, and the effect on the standards of observational skill will plainly become more serious the longer the unification is delayed. It is therefore much to be hoped that the authorities concerned will realise the very pressing need to accelerate the present slow progress; in the long run it would result in a financial saving.
From the point of view of its preservation as an Ancient, Monument, the Castle will also require some fairly substantial expenditure before very long. An extensive stretch of the old garden wall blew down in one of the winter gales; no funds are at present available for its repair and it appears possible that a further fall is imminent. The bridge over the north moat is also in a state of disrepair, caused by the ravages of the ivy, with which it was overgrown.
Although the hostel arrangements will cater reasonably well for unmarried staff, no quarters are yet available for married men. Admiralty action has recently been taken to obtain a small allocation of "traditional" houses from the Ministry at Health, and it is believed that Hailsham Rural District Council is prepared to erect these when they are in fact authorized. Their number is only sufficient for Stage I. But apart from these few, married members of the staff, some of whom have had as much as six years war service, will be faced with a separation-period which h likely to last for a year at least. The continuance of a similar situation through all later stages of the move would cause grave dissatisfaction and discouragement, and would be bound to have an adverse effect, on the smooth running of the Observatory. It is evident that further official action on a somewhat increased scale will be essential if the later stages are not to fare even worse than the first, and if they are to fare better in any way a different approach to the subject is called for. Astronomer Royal has included in his proposals to Admiralty a requirement for houses for, senior Observing staff; these could be built on the edge of the Observatory property, and would have the advantage, from the official point of view, that members of the staff could be required to vacate them when they retired; this is not of course, the case with housing provided by Local Authorities. The nature of night observing duties requires observing staff to be resident within easy access of the Observatory; otherwise loss of observations is inevitable at times when the sky clears suddenly. It is fairly normal for an Observatory to be provided with houses for observing staff and it is really essential when, as at Herstmonceux, the Observatory is in an isolated area. The need did not exist at Greenwich, from the nature of the situation in a closely built-up area. The Local Authority is not in any case prepared to supply houses (within any foreseeable period) for personnel not already on the Observatory staff; the Observatory at present lacks a Chief Assistant, a Superintendent of the Magnetic and Meteorological Department, a senior Assistant in the Nautical Almanac Office, a Librarian and several Watch Repairers. A number of additional vacancies for senior scientists will occur when the new complement becomes effective, and a proportion of those who would be suitable for such positions will certainly be married men; there is a serious likelihood that they will refuse to consider any offer under present conditions, since it would mean a separation from their families of altogether indefinite extent. There is evidently a grave risk that the increase incomp1ement, which has been approved in principle, may be nullified in practice through an unrealistic approach to the housing problem, quite apart from the general hardship which is, as yet, the only prospect for existing married staff of the later stages.
The Report here presented refers to the period from 1948 May 1 to 1949 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
(a) Greenwich. All glass has been replaced, and windows and doors have been repaired, in the South Building. Temporary repairs in the north attic have also been carried out here, and the ceiling of the upper museum has been made good. Some re-wiring has been done, especially of workshop machines and lights. In the Central Store new window-sashes and door have been fitted, the roof has been repaired, new gutters and drainpipes have been installed and external painting has been carried out. In the Old Building, all damaged ceilings and walls have been replastered, and broken sashes have been replaced in the Airy Transit Circle room; some items of damage still remain however. The old Cookson hut has been fitted up to accommodate a petrol-driven A. C. generator which has been obtained in order to have a standby power-source for the quartz clock installation. The external steps to the roof of Flamsteed House have been extensively repaired, the balustrade and anemometer huts have been redecorated, and the roof over the Ball Lobby has been re-slated. A survey of the photoheliograph dome revealed dangerous weakness; the coping has been removed and the walls rendered. Flamsteed House and the Octagon room have had no further attention yet; the Octagon room in particular still lacks glass, and has blast damage which it may be difficult to make good in a suitable manner. The boundary fence of the Christie Enclosure has been repaired and strengthened with metal strip, as odd slats had repeatedly been forced out and thermometers stolen. Stevenson screens have been repaired and the metal-work of the Yapp dome has been repainted.
(b) Abinger. The premises at "Cornerways", Abinger Hammer, which were requisitioned during the war for use as offices and which, since the war, have been used as a staff hostel were vacated at the end of 1948. Negotiations for the tenancy of "Feldemore", Holmbury St. Mary, referred to in the previous report, were completed. The hostel was transferred there in January, 149. The house provides also some office and storage accommodation for the Time Department and accommodation for seven married members of the staff.
Several of the halyards on the masts supporting the aerials on Wotton Common were broken during heavy gales. The masts were lowered for fitting new halyards and subsequently re-erected.
(c) Herstmonceux. The Astronomer Royal's residence, the Main Office, and the Head Messenger's cottage were completed and occupied in August and September; the Chronometer Department office, with the temporary chronometer rooms in the southwest first floor and the Chronometer Workshop in one of the huts, were completed soon after, and the Chronometer Department moved from Bradford-on-Avon in September. The second-floor hostel quarters in the Castle, the hostel common rooms in the huts, the remaining hostel bedrooms there, and the Refectory in the Castle were completed and taken into use as necessary about the same time. The premises occupied by the Chronometer Department at Bradford-on-Avon have been given up. The generous cooperation of the Hailsham Borough Council provided the Observatory with six houses from their Bagham Lane group, more than a year ahead of any which will be available from the special allocation made for the Observatory, and these six houses were just sufficient for the existing married staff from Bradford-on-Avon. The lack of houses for any other married staff has so far prevented the Nautical Almanac Office and the Magnetic and Meteorological Department from moving. The accommodation for the Nautical Almanac Office, in one of the huts, is ready for occupation. The Magnetic and Meteorological Department offices are not yet ready, but can be completed fairly rapidly when the need arises.
The Solar Building and the Solar Department offices were completed in April, with the Newbegin dome mounted on the building and painted, and coelostat piers for both the Newbegin and the Greenwich spectrohelioscopes erected on the south side. Final painting of the dome walls has been deferred, and linoleum is to be laid in the dome but this has been postponed until the work of mounting the telescope is complete. The building was designed to have quarter-circle curves at the two corners on the south-west, but the Civil Engineer found it impossible, when the time came, to obtain curved bricks of the kind which had been selected for the building, and ordinary square corners were substituted. The bricks were intended to match those of the Castle, but these have, of course, aged in the course of centuries; it is possible that time will diminish the present contrast. The cellar adjoining the building, which is planned for large prisms, has been started.
Reconstruction of the floor of the Great Hall, to enable it to carry the weight of books, is nearly complete, and the chronometer rooms, darkroom, and other quarters below it have been progressed. It is hoped to transfer the chronometers and watches from their present temporary quarters fairly soon, so that the rooms at present occupied by them may also be adapted for their permanent purpose.
The Report here presented refers to the period from 1949 May I to 1950 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
(a) Greenwich. Little further work has been done during the year towards repairing the remaining war damage., but it is hoped that some major steps will be taken shortly. The two large domes are in bad condition, and tarpauline inside them only partially cope with rainwater. The Octagon room, Flamsteed's Observatory, built by Wren, is still without glass, and requires considerable internal repair. The dilapidated condition of the historic buildings has given rise to much adverse comment, while the delay in carrying out repairs is causing
further deterioration in condition.
General repair work on a limited scale, including repair of boundary- fences, has been carried out. The Airy pavilion shutters have been repaired, but the roof is still not in satisfactory condition. A considerable amount of external painting is due to be done in the coming year.
The industrial staff have been much occupied with the mechanical aspects of the move; about 1500 feet run of bookshelves have been transferred from the Central Store at Greenwich to the West Hut at Herstmonceux, and all stock volumes of Greenwich and Cape Observations (several thousand books), as well as about twenty-two thousand 10" x 10" solar plates, have been safely moved and re-housed, The transfer of the photoheliograph from its old mounting at Greenwich to the Newbegin at Herstmonceux had been so fully rehearsed that the instrument actually took photographs of the Sun at Greenwich before its removal, and at Herstmonceux after it, on the same day.
(b) Abinger. A new septic tank has been supplied. At "Feldemore", where the water supply had not proved satisfactory, a new system has been installed.
(c) Herstmonceux. During the year, the move of the Solar Department was completed, the Nautical Almanac Office moved from Bath, and the section of the Magnetic and Meteorological Department which was at Greenwich moved in part. Two members of that Department remain at Greenwich, to carry on the meteorological observations and reduction, and to assist in the meridian observations
In January it was announced that Mr. B. O'Rorke , A. R. A. , F. R. I. B. A. , had been appointed by Admiralty as consulting architect for the Herstmonceux scheme as a whole. This welcome step will undoubtedly ensure the maximum advantage to the Observatory in the long run, but it appears to have introduced some additional delay at the present stage. The Civil Engineer-in-Chief is retaining responsibility for the Meridian Group of instruments, but is not prepared to commence any one of them, nor to ask the Architect to begin any of the others, until detailed requirements for buildings in every group have been supplied; this has meant that a considerable amount of design and planning, which would have been spread over two years, has had to be compressed into one, in spite of the continued absence of a second Chief Assistant and the serious amount 'of disorganisation and duplication of effort which the move involves at all s Nearly all the necessary information has now been supplied, so far as is known except for the matter of the permanent hostel, where requirements are still difficult to foresee.
The installation of the Meridian Group involves a great deal more than merely moving and re-erecting existing instruments. The Photographic Zenith Tube is a new instrument, not yet completed. The Melbourne Transit Circle is new so far as Greenwich is concerned and has no pavilion at present. The Cooke Transit Circle (R.T.C.) requires two fundamental changes, which affect the design of its pavilion; on the one hand, it is intended to give it azimuth-marks, which were not provided for in the Greenwich situation but which are essential for a full determination of the azimuth; and on the other hand it is intended to house the collimators in the main pavilion, instead of in two adjacent ones, since the determination of collimation is often practically impossible by day, and is unsatisfactory even by night with external collimators. Since even in the site now selected the angle of depression to the azimuth-marks cannot much exceed three degrees, these two requirements together have the consequence that the pavilion cannot be much less than 48 feet long, (instead of the present 30 feet), unless either the collimators are made movable (and are moved whenever the azimuth-marks are observed), or the collimators are "broken" by a plane reflection. It has been decided not to risk either of these expedients for the primary meridian circle of the Observatory, but instead to design a new pavilion for it, and to use the existing pavilion for the Melbourne instrument. Full details for the Greenwich instrument have been supplied to the Civil Engineer-in-Chief; it is proposed to mount the instrument and both collimators on a single reinforced concrete block, and to have a pavilion with a relatively low-pitched roof, the ridge being east-west.
To house the Melbourne instrument in the present R.T.C, pavilion, the collimators will have to be broken; but as the instrument will be used for differential work only, this is not serious. Useful information on the stability of such an arrangement will be obtained, and may influence the design of the proposed mirror transit-circle. It is intended that the Melbourne instrument also shall have a single concrete foundation, and the layout has been discussed and decided. Provision is being made for increasing the focal lengths of the collimators to equality with that of the instrument; the wires cannot otherwise appear of the same thickness when viewed through the telescope as when viewed through the other collimator; a difference in appearance is liable to introduce systematic effects.
It had originally been intended to set up the Melbourne Circle at Herstmonceux before removing the Cooke R.T.C, from Greenwich, but it has now been decided to move the Cooke first. This is a result of the decision that it is to be the Cooke instrument which has the new pavilion. It is hoped that work on the new pavilion may start very shortly; the Cooke transit circle will then in due course be dismantled and re-erected at Herstmonceux, after which the pavilion at Greenwich will be dismantled and re-erected at Herstmonceux to house the Melbourne transit circle.
The Meridian Group will include, in addition to these two major items, pavilions for the P.Z.T. and the Bamberg Small Transit, and also a small building comprising control-room for the P..Z.T., an observers' room, and accessory services. The planning of these items is in an advanced stage.
Requirements for the combined Nautical Almanac and Time Department building were specified to the Civil Engineer-in-Chief in considerable detail; appreciable parts of the Time Department building are almost as strictly functional as a telescope-dome, and even for the N.A.O. it was thought desirable to go into much more detail than a list of floor-areas would provide. All major requirements for this building, for the workshop and chronometer repair shop, and for the Equatorial Group (six telescopes) were worked out and submitted during 1949. It has been urged that the buildings for the 26-inch and 28-inch refractors should be constructed as early as possible. A rising floor is planned for the 26-inch refractor dome, and this will involve close cooperation between the Architect and the engineering firm which will supply the floor. The telescope is at present undergoing extensive overhaul and modification by Messrs. Grubb, Parsons, in addition to having the 30-inch reflector detached and replaced by a counterpoise. The drive of the 28-inch is also being modified, a synchronous motor and Grubb controls being substituted for the Gerrish arrangement.
The Equatorial Group is planned to have three isolated domes for the 26-inch, 28-inch, and Astrographic refractors, with a three-dome building in front of them to take the 30-inch and 36-inch reflectors, and also a Schmidt plate camera of about 25-38 inches, together with aluminising room and plant, plate-standardising laboratory, darkrooms for the whole group, and probably some spare space which can be used for storage until it is otherwise required. It is planned to have the 30-inch and 36-inch reflectors able to "see into each other”, so that either of them can be fed from the other with a nearly-parallel full-aperture beam for calibration work. A raised flat roof between will allow full-aperture screens to be erected if desired, and will give considerable freedom for a wide range of tests and operations. Arrangements will be made for lowering each of the three main mirrors through the floor of its dome, and all of them can thus be transported to the aluminising room without encountering any steps. The aluminising plant will serve also as a pilot-model for the one that will be needed by the Isaac Newton Observatory later.
With the installation of the two spectrohelioscopes, the Solar Building is now essentially complete. The spectroheliograph cellar is not yet finished, but as the prisms which it is intended to install there are still in active use by their present owner there is no effective delay here. Plans for the housing of the central coelostat, which will feed the two tunnels, have been agreed with the Civil Engineer; this work will be completed shortly. The air conditioning arrangements are all ready to install as soon as the cellar is closed in.
The Great Hall of the Castle is being adapted as the Library. The steelwork for supporting the gallery is now complete, and the layout of the bookshelves has been determined. The most suitable method of lighting the Library is under consideration. Conversion of the permanent chronometer rating and storage rooms under the Great Hall was completed during the year and these rooms have been brought into use. The offices for the Magnetic and Meteorological Department have been completed; those for the Department of Astrometry and Astrophysics are practically complete also. No work has yet been done on the rooms for the Meridian Department, while a fair amount of work is outstanding in the rooms to be used for the Optics Laboratory.
Housing difficulties have proved the limiting factor on most stages of the move which have taken place so far. The Council houses which have been made available by a special allocation of the Ministry of Health have so far proved sufficient for the immediate needs of junior and industrial staff, but they are not suitable for more senior staff. The continued lack of houses of superior type has already proved a definite handicap to recruitment to vacancies in senior grades. It appears that the only satisfactory solution is for Admiralty to build houses suitable to the status of the officers concerned. No decision has yet been given on the proposal that houses should be built by the Admiralty for occupation by senior observing staff, who should be resident in fairly close proximity to the Observatory.
The Report here presented refers to the period from 1950 May 1 to 1951 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS
(a) Greenwich. Further repair of war damage has been carried out. Flamsteed House itself, including the historic Octagon Room, has now passed out of the jurisdiction of the Observatory. The House has been converted into two flats for Naval Officers of the Royal Naval College, and it has been occupied by them since March 3. The Wren building has been taken over by the Ministry of Works, and it is understood that it will be treated as an Ancient Monument. Repair work is in progress; it is found that extensive dry rot has developed, as a result of the neglect to replace windows and to repair other war damage. The Ball-Lobby had been provisionally repaired in advance of this work, the Ball mechanism repaired and replaced, and all arrangements made for dropping the Time Ball again daily, starting on the first day of the Festival of Britain.
In the Old Building and Airy T. C. pavilion, all damaged window-sashes and frames have been replaced, and the roof has been overhauled. The covered way, and the greenhouse on the courtyard side of Flamsteed House, have been removed. A new door and frame have been provided from the courtyard to the Airy T.C. pavilion, the transom above the old one being bricked up and the wooden porch removed. Leaks in the Astrographic dome have been repaired, and the old Small Transit pavilion roof has been repaired and re-covered.
The covering of the 28-inch dome, which was badly damaged and most unsightly, has been removed, and a horizontal corrugated-iron roof has been laid, a little above the dome-rail, the entire framework of the dome being still in place, though steadily deteriorating. The Civil Engineer, Deptford, has attached a couple of panels of sheet aluminium to the framework, to test its suitability for re-covering, supposing it is decided to preserve the dome as a landmark. The dome, though a characteristic feature of the Observatory in recent times, is, however, only about 60 years old, while the building on which it stands is ill-adapted for any useful purpose.
The "New Building" is still in need of further work. The Thompson dome has been partly repaired but still leaks, and much of the bomb-damage to the building itself has had only temporary repairs. A serious gas-leak in the building was discovered, and the entire service was disconnected and replaced by fresh connections to the workshop and the toilet hot-water supplies, the only points at which gas is now required. The hot-air furnaces had been feeding carbon monoxide to the rooms for some time, and on investigation cracks leading from the flues to the air-ducts were discovered. Temporary repairs have been made, and it is hoped to do more during the summer.
Exterior painting has been done on the Old Building, (including the Airy T.C, shutters), the Porter's Lodge, the steelwork of the Cooke T.C. pavilion, and the Yapp reflector dome. Parts of the Cooke pavilion steelwork are not accessible, and on removal to Herstmonceux the construction will have to be modified. Interior decoration has been done in the Altazimuth dome (housing the small transit), the Porter's Lodge, and the Ladies' rest room and toilets.
The transfer of shelves, records, and stocks of Greenwich and Cape publications from Greenwich has proceeded, involving nearly continuous weekly deliveries by road transport.
(b) Abinger. A, new generator house has been erected to house the emergency power supply equipment. A bathroom has been added to the Caretaker’s residence.
(c) Herstmonceux. No actual work has yet started on the sites op either the meridian group or the equatorial groups, but planning has proceeded. The exact locations have been selected for the individual meridian instruments, with the differences in latitude and longitude adjusted for convenience to integral multiples of 1/10" and 10 milliseconds respectively. Lines have been, surveyed out to the proposed azimuth-marks for both the Cooke and the Melbourne Transit-Circles. The positions which had been provisionally selected for the P.Z.T, and the Bamberg were altered, in April, to facilitate a re-location of the P.Z.T. control-room and observers' building, in conformity with the views of the Architect. Tenders have been invited for the Cooke R.T.C. Pavilion. The general layout of the Equatorial group has been agreed with the Architect. The three-dome building to house the reflectors, referred to in the last report, is now to be north of the three isolated refractor domes, but its general arrangement and functions are still essentially as originally outlined in 1947. The appearance, both individually and for the group as a whole, owes very much indeed to the Architect, and it is considered that the final result will be satisfactory both functionally and aesthetically: it is pleasant to record that there has been no pressure to sacrifice any functional requirement, however trivial, to other considerations. The Architect's proposals include a layout for a number of official staff houses, but the question of actual approval to build these is still outstanding.
A run-off housing for the coelostat of the spectroheliograph cellar has been completed and installed, and the air-conditioning has been installed and tested. Seepage of water into the cellar has given trouble and work is in hand to correct it. A coelostat-mounting, arranged for the primary mirror to traverse from NE to NW of the secondary one, has been provisionally designed, but it is not yet known whether parts of some existing mounting can be used in this.
The adaptation of the Great Hall of the Castle as a library is nearly complete. The constructional work and the decorations have been completed; cork tiles have been laid on the floor, including the gallery floor, and hot water radiators have been installed. The lighting installation is under consideration. Tenders for the supply of shelving will soon be invited. The offices for the Department of Astrometry and Astrophysics, and the rooms to be used for the Optics Laboratory have been completed.
Much progress has been made in fencing the grounds, the fencing material being obtained from the woodland areas. These areas have been thinned where necessary to improve their condition, and an appreciable revenue has been obtained from the sale of timber.
The grounds are open to the Public on Wednesday and Thursday afternoons each week from April to October inclusive at a charge of 1s. per head, so that the Public has an opportunity of seeing the historic Castle and the gardens.
The Report here presented refers to the period from 1951 May 1 to 1952 April 30 and exhibits the state of the Observatory on the last named day.
I. Grounds and Buildings.
(a) Greenwich. As mentioned in last year's report, the Wren building has been taken over by the Ministry of Works, and will be treated as an Historic Monument. Extensive dry rot was found in the roof and particularly in the main supporting beams; the delay in repairing war damage and the lack of windows for some twelve years were undoubtedly contributory factors. Rolled steel joists have been inserted temporarily to carry the weight from above, by means of straps and bolts passing through the lead flats. While the repairs to the roof are in progress, a temporary roof has been provided over the octagon Room. The replacement of all damaged woodwork has been completed and work on the ceiling is in progress.
The exterior painting of the south side of the Old Building and of the Airy Transit Circle pavilion, and the interior painting of the main floor of the New Building, of the Gate Porter's Lodge and of the Sheepshanks dome have been completed. The old covering of the Thompson dome has been replaced with aluminium sheeting. Extensive repairs to the Sheepshanks dome and abutters have been carried out. The window arches on the south side of the Photoheliograph dome have been rebuilt and a portion of the wall has been repointed.
The hot air furnaces of the New Building have been overhauled and the ducts have been repaired. Though the system is now in a satisfactory condition, the special grade of anthracite for which the system was designed is no longer available, and a suitable substitute has not yet been obtained. The provision of a Ladies' Toilet in the Old Building, work on which was started in 1940 but shelved during the war, has been completed.
In the Christie Enclosure, the exterior steelwork of the Cooke Reversible Transit Circle pavilion and of the Yapp dome, and the louvres of the collimator houses have been repainted.
(b) Abinger. The walls of the Time Department Building and of the Laboratories have been treated with a water-proofing solution. All unpainted exterior woodwork at Feldemore has been treated with wood preservative.
(c) Herstmonceux. The Ministry of Works has taken over responsibility for the maintenance of the exterior walls of the Castle, which are of the original brickwork. The replacement of portions of the stonework of the south gateway and towers, which have weathered badly, is making slow progress; it has already extended over more than two years. Meanwhile, the two state bedrooms over the gateway, reserved for the use of official visitors, remain out of use.
The roadway to the east gate has been regraded, widened, and provided with a proper foundation and drainage. It will give access to the Equatorial Group on the north and to the Isaac Newton Reflector on the south. A temporary roadway has been laid to provide access to the Meridian Group during its construction.
The contract has been placed for the pavilion to house the Cooke Reversible Transit Circle. Contracts for the building to house the Photographic Zenith Tube, the building to hold the control console for this instrument, and the pavilion for the Bamberg Broken Transit Instrument are due to be placed. The foundations and piers for the instruments and the foundations for the buildings themselves are to be constructed departmentally. After the Cooke R.T.C. has been erected at Herstmonceux, the pavilion which houses it at Greenwich will be dismantled and re-erected at Herstmonceux to house the Melbourne R.T.C.
The Consulting Architect has progressed the designs for the Equatorial Group of six telescopes. All details have been settled and the plans are now in an advanced stage. It had been hoped to start construction of this group this summer but, as a consequence of the economy drive, it has been decided that the work cannot be started during the present financial year,
Preliminary plane of the building to house the Time Department, the Nautical Almanac Office, the Workshops and to provide storage accommodation have been prepared by the Architect as a basis for discussion.
The adaptation of the Great Hall of the Castle as a library has been completed, except for the lighting, the installation of which is in progress. The main entrance doorway has been reconstructed and new doors have been provided. The shelving for the books has been constructed and erected by Messrs. Libraco Ltd., who have also supplied card catalogues and other accessories. The large oak table from the Octagon Room at Greenwich has been brought to Herstmonceux and placed in the library for the display of current periodicals and publications. The removal of the library books from Greenwich to Herstmonceux has commenced.
As a first stage in the scheme for landscaping in and around the groups of instruments, several areas have been planted with trees and shrubs and protected with rabbit proof fencing.
A messenger's lobby has been provided within the west entrance of the Castle. The black paint has been removed from the main staircase, the surrounds, and the two doors on the first floor; the woodwork has been lightly stained and polished. The beautiful carved woodwork of this magnificent staircase can now be seen to full advantage.
The adaptation of the two rooms on the ground floor on the north side of the Castle, which will provide office accommodation for the Meridian Department, has been commenced.
Borings have been made on the sites of the principal instruments for consideration by the Consulting Engineers, to provide a basis for deciding how deep it is necessary for the piers to extend. Surveys of these sites have been in progress to provide the Architect with precise information about differences of level.
The Report here presented refers to the period from 1952 May 1 to 1953 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS
(a) Greenwich. Repairs to the structure of the Wren building have been completed, and the Octagon Room and staircase have been painted, by the Ministry of Works; the colour scheme is cream and saxe blue, which are thought to be the original shades; the windows have been fitted with leaded glass, artificially imperfect, to resemble those shown in drawings of Flamsteed's time. Linoleum to match that in the Maritime Museum has been laid, both there and in the Airy Transit Circle pavilion, and some cases of exhibits have been brought up from the Museum and put on display. The Bradley Zenith Sector has been removed from the Airy pavilion, where it had hung since its return from South Africa in 1851, and the brasswork and sector have been cleaned by the British Museum; the plumb-bob and various auxiliary items are missing, and duplicates may be made later. The tube itself has been cleaned by the Maritime Museum, and a wooden pier is being constructed for it there; this will be painted to resemble stone, but is a light-weight structure suitable for museum display. The Halley Transit is being provided with a similar pier by the Observatory, and both instruments will be set up in the Octagon Room for the present. Photographic copies of various old prints, generally of Flamsteed's, time, are being prepared for hanging on the walls. A temporary loan is being made to the Maritime Museum of some of the important old manuscripts in the Observatory's possession, for showing in the Octagon Room, which is to be formally opened by H.R.H. the Duke of Edinburgh on May 8th. The Octagon Room will thereafter be accessible to the public at regular Museum hours, warders being provided by the Museum. The Airy Transit Circle may be shown to visitors in addition, subject to its not being in use for observation at the time. In preparation for the opening, the Ministry of Works have resurfaced the courtyard and repainted the Main Gates; they have also replaced the stone "meridian line", in the path outside the Observatory, with a more prominent line, sunk into larger stones.
The Time Ball was brought into operation again on October 26th and has been dropped at 1300 daily since then, with occasional exceptions due to dangerously high winds, or to the need for minor adjustments.
The Lower Store has been given up to the Ministry of Works and conversion work is now proceeding on it. The mirror-grinding machine housed in it has been disposed of and all the other contents have been removed to the Central Store.
The removal of books from the Library to Herstmonceux, which is being carried out by the Workshop staff, is now nearing completion; about 24000 volumes have been transported and placed in the new library there. Some of the shelving from Greenwich has been transferred to the huts at Herstmonceux, and will be used for storing some of the contents of the Greenwich Record Rooms.
The main office of the Time Department was transferred to the old Wireless Room in October, at which time the Control Room, which had been serving both functions, was repainted. Internal painting has also been carried out in the Astrographic dome, and on the staircase and landing leading to the new Time Department office and to the Sheepshanks dome. In the New Building, the entrance, general office and adjacent rooms, and the Foreman's office, have also been painted. Exterior painting on the north side of the Old Building, the Control Room and Chart Room and on the Astrographic and Altazimuth domes has been completed.
(b) Abinger. The domestic water supply to Feldemore is drawn from the supply mains and fed to storage tanks in the roof by means of an electrically-driven booster pump. This system has given much trouble from repeated failures; various modifications to the pump and motor have not resulted in any permanent improvement. A new pump and motor have now been obtained, and will be fitted shortly.
Considerable inconvenience to the operational work of the Time Service has been caused by the large variations in the voltage of the mains electricity supply. As a result of discussions with the Electrical Engineering Manager, Chatham, and the Supply Authority, a static balancer has been installed as a temporary measure, pending modifications in the supply arrangements.
(c) Herstmonceux. The replacement of portions of the stonework of the south gateway and towers of the Castle has continued throughout the year. This work is being carried out by the Ministry of Works, who have accepted responsibility for the maintenance of the external fabric of the Castle.
The large wooden hut within the courtyard of the Castle has been dismantled and removed, thereby much improving the appearance of the courtyard. This is the first of the temporary buildings, erected during the war by the Hearts of Oak Friendly Society and acquired by the Admiralty with the Castle, to be removed.
The lighting of the Great Hall of the Castle, which has been adapted as a library, has been completed except for the reading lamps on the tables. Strip lights have been fitted in each bay between the book stacks under the gallery, and along both sides of each row of stacks in the gallery. Three specially designed fittings provide general illumination. The books brought from Greenwich have been arranged in the library, but not all are as yet in their final places.
The verges of the roadway to the east gate, which will give access to the Equatorial Group and to the Isaac Newton reflector, have been turfed. The area of the Meteorological Enclosure has been levelled and fenced; the housing for the anemograph recorder is nearing completion.
The foundations for the Control Building for the Photographic Zenith Tube were completed several months ago. The erection of the building itself, which is largely of wooden construction and of a prefabricated nature, was deferred until the spring and is now in progress.
In order to provide the maximum degree of stability for the large pier, which is to carry the Cooke Reversible Transit Circle and the two collimators, it was decided to support the pier on piles. Twelve piles have been driven to a depth of 34 feet 6 inches below the ground surface. The piles are of reinforced concrete; the steel reinforcing rods will be bent over at the top and will be incorporated in the pier, thus integrating the pier with the piles.
Contracts have been let for the manufacture and erection of the buildings to house the Cooke R.T.C., the Photographic Zenith Tube, and the Bamberg Small Transit, The foundations for each of these buildings, as well as the piers for the telescopes, will be done Departmentally. The expected completion dates for these buildings will be much delayed, but it is still hoped that the buildings will all be erected by the end of the present year.
In connexion with the retriangulation of the United Kingdom, the Ordnance Survey is to fix a datum point in a position that has been selected to the south of the site for the Isaac Newton telescope. When the base plate of the Cooke R. T. C. has been placed in position and before the walls of its housing have been erected, the position of the base plate relative to the datum point will be determined. It will thus be possible to derive an accurate geodetic connexion between the Cooke R. T. C, at Herstmonceux and the Airy T. C. at Greenwich.
The working drawings for the Equatorial Group of instruments have been completed. Tenders for the steel work have been invited. It is expected that it will be possible to accept a tender for the buildings before the end of the summer.
Preliminary plans of the buildings to house the Time Department and Nautical Almanac office, the Observatory Workshop, the Chronometer Repair Shop, and to provide miscellaneous storage accommodation and a works pound, have been considered. Some modifications to these plans were required and revised plans are in course of preparation- It is hoped that it will prove possible to accept a tender for construction by the spring of 1954.
Several further areas have been planted with trees, shrubs, or hedges in accordance with the scheme for landscaping.
The Report here presented refers to the period from 1953 May 1 to 1954 April 30 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
(a) Greenwich. The Octagon Room, which had been handed over to the National Maritime Museum as described in last year's Report, was formally opened by H. R. H. the Duke of Edinburgh on May 8. It has been accessible to the public at regular Museum hours, warders being provided by the Museum. Halley's Transit and Bradley's Zenith Sector are displayed in this room, together with copies of various old prints of the Observatory. Some important old manuscripts in the possession of the Observatory were exhibited for most of the year. The Airy Transit Circle has been shown to visitors, subject to not being in use for observation at the time.
The workshop, staircase, "museum" floor, and exterior of the New Building have been painted, and downpipes which suffered war damage are being replaced. The hot-air furnaces have been overhauled. In the old buildings, repair and maintenance work has been done on the battery room and toilets, the vinery, and the cold house. Boundary fences have been repaired and strengthened. A new boiler has been installed for heating the Record Rooms and Time Department Office.
The Time Ball has been dropped regularly, exceptions being made (on account of high winds) on January 15, March 1, and March 2.
(b) Abinger. At Feldemore, an additional flat has been provided, as the requirements for hostel accommodation had decreased. A new septic tank has been installed, serving the drainage system of the stables block. The cold water supply pipe from the pump house to Feldemore has been replaced.
(c) Herstmonceux. In connexion with the maintenance of the external fabric of the Castle by the Ministry of Works, the replacement of portions of the stonework of the south gateway, which were badly weathered, has been completed. Repairs to the west tower of this gateway are in progress.
The Meteorological Enclosure, including the building to house the anemograph recorder, has been completed. Regular meteorological observations were commenced on November 1.
In the Meridian Group, the Control Building for the Photographic Zenith Tube has been completed. The pavilion for the Cooke Reversible Transit Circle was erected for tests at the makers' works in July. Some modifications to the gear for operating the roof-shutters were found to be required. After these changes had been made, the structure was dismantled and sent to Herstmonceux. The concrete foundations for the building and the massive pier to carry the instrument and collimators had meanwhile been constructed by Departmental labour. The base casting of the instrument was placed in position before the erection of the pavilion was commenced. The pavilion was completed in March, except for external painting and the provision of the entrance steps.
The foundations for the Photographic Zenith-Tube Pavilion are under construction and the manufacture of the pavilion is well in hand at the works of the contractors. The plans for the pavilion to house the Bamberg Small Transit are nearing completion. It had been expected that both of these buildings would have been completed during the year, but there have been further delays. It is hoped that both buildings will be erected by the end of July 1954. The pavilion which housed the Cooke R. T. C. at Greenwich is to be modified to house the Melbourne R. T. C., together with its two collimators, at Herstmonceux. The drawings of the modifications are in hand.
Work on the Equatorial Group was started in October. The whole of the steelwork for the Laboratory Block is complete and the foundations and walls for the domes are in hand. The details of the designs for the domes have been settled. The building contract for the group is due to be completed by July 1955.
The details of the design of the building to house the Nautical Almanac Office, Time Department, workshops and associated buildings have been under discussion. The Consulting Architect has not made the progress expected on the working drawings and the commencement of the work on site has accordingly been delayed. It is hoped, nevertheless, that an early start will be made on this building.
Works on roads, drains and landscape gardening has continued by Departmental labour.
The Report here presented refers to the period from 1954 May 1 to 1955 March 31 and exhibits the state of the Observatory on the last named day.
Owing to the railway strike, the Annual Visitation and reading of this report was postponed from 1955 June 4 to 1955 July 9.
I. GROUNDS AND BUILDINGS.
(a) Greenwich. The downpipes of the New Building, which were damaged in the war, have now been replaced, but there is still some roof damage that has been only provisionally repaired. The hot air furnaces have again been overhauled. Owing to the shortage of rough storage space which followed from the surrender of the Lower Store to the Ministry of Works, it has been found necessary to repair and use some of the old "stable" sheds. Some of the upper floor rooms, which are no longer required, have been temporarily lent to the Maritime Museum for storage of figureheads and other "Cutty Sark" exhibits. In the old buildings, interior decorations have been carried out in the chart-room, landing, and astrographic dome and staircase.
A further quantity of library shelving was removed from Greenwich and erected in a temporary hut at Herstmonceux, for record storage.
(b) Abinger. The Admiralty Civilian Hostel at Feldemore, Holmbury St. Mary, which in the past nine years has provided accommodation for many of the staff employed at Abinger, was closed on February 13. Some of the rooms which have been set free are in temporary use as -a flat: the remaining rooms will be used for stores and other official purposes.
The instruments and equipment of the Physics and Optics Laboratory are in course of transfer to Herstmonceux. The accommodation set free will be used jointly by the Electronics Laboratory and the Maintenance and Installation Section of the Time Department.
(c) Herstmonceux. In connexion with the maintenance of the external fabric of the Castle by the Ministry of Works, repairs have been in progress to the west tower of the south gateway and are now nearing completion. Portions of the stonework, which were badly weathered, have been rebuilt; the upper portion of the tower, which was in a not very safe condition, was dismantled and has been rebuilt.
In the Meridian Group of buildings, the painting of the Cooke Reversible Transit Circle building was completed and the entrance steps were provided. The small pavilion to house the Bamberg Small Transit and the pavilion for the Photographic Zenith Tube have been erected. A few modifications to the latter building are required before final acceptance. It has been decided to erect a new pavilion for the Melbourne Reversible Transit Circle, generally similar in design and dimensions to the Cooke R.T.C. pavilion and with similar foundations, deeply piled for stability, for the instrument and collimators. The earlier proposal, to modify the existing Cooke R.T.C. pavilion at Greenwich and to transfer it to Herstmonceux, has been dropped.
Considerable progress has been made with the construction of the Equatorial Group. The steel frameworks of three of the six domes - those of the 30-inch reflector, the Schmidt reflector, and the 26-inch refractor - have been erected, but the cladding of these domes has been seriously delayed by the designs of the mechanisms for operating the dome shutters not having been completed. It is planned to commence the erection of the telescopes In this group a-s soon as the domes have been completed.
The base casting of the 26-inch refractor was lifted on to the concrete pier on November 26, when it was found that the pier was slightly too small. It will be possible for the casting to be rolled off on to a staging and the pier sufficiently modified before the erection of the telescope is commenced. The main north and south castings of the 28-inch refractor were placed in the dome on February 28, but will not be erected and grouted in until a later stage.
The foundations for the West Building, which will house the Nautical Almanac Office, the Time Department and the workshops and which will also provide miscellaneous storage accommodation, have been commenced and are in an advanced stage of construction. The erection of the steel framework of this building has been commenced.
(d) Hartland. The site at Hartland, N. Devon, selected as the future site for the Magnetic Observatory, which is to be transferred from Abinger because of the disturbing effects of the electrified railway system in its vicinity, has been purchased. Detailed drawings of the buildings to be erected there have been prepared by the Civil Engineer-in-Chief. The building is expected to be commenced shortly to ensure its completion in time for observations to be commenced before the beginning of the International Geophysical Year. Samples of the building materials to be used are being tested at Abinger to ensure that the materials are completely non-magnetic.
One of the buildings to be used for the testing of magnetic instruments will contain a system of large coils designed to provide artificial horizontal and vertical fields, comparable with those at any point upon the surface of the Earth. Details of this system have been discussed but it has been decided that, until the engineering problems have been settled, one end of the building designed to house these coils will be left temporarily open to ensure the necessary access for the castings.
The Report here presented refers to the period from 1955 April 1 to 1956 March 31 and exhibits the state of the Observatory on the last named day.
Sir Harold Spencer Jones retired from the Office of Astronomer Royal on 31 December. The observations referred to in the present Report were thus mostly made under his direction.
I. GROUNDS AND BUILDINGS.
(a) Greenwich and Abinger. A minimum of redecoration, repair and maintenance work has been carried out, pending a total evacuation of the buildings.
The Halley Transit Instrument and the Bradley Zenith Tube, as objects of historical interest, have been handed over to the National Maritime Museum as exhibits in their astronomical annexe.
(b) Herstmonceux. Construction of the Equatorial Group of domes and buildings is still under way, but no dome is yet complete and no telescopes have yet been installed.
The main fabric of the West Building has now reached an advanced stage of construction.
The pavilions for the Photographic Zenith Tube and the Cooke Reversible Transit Circle were completed during the year.
Part of the Observatory Workshop has been transferred from Greenwich into temporary quarters pending completion of the West Building.
(c) Hartland. Building of the new magnetic observatory at Hartland commenced in the early summer and has progressed according to schedule.
The Report here presented refers to the period from 1956 April 1 to 1957 March 31 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
(a) Greenwich and Abinger. The grounds and buildings at Greenwich and Abinger have not been completely vacated.
(b) Herstmonceux. The Equatorial Group has not yet been handed over to the Royal Greenwich Observatory, but by special arrangement parts of telescopes have been installed in certain domes. The aluminising plant has been set up in the Equatorial Group and has been used satisfactorily.
The West Block has not been handed over to the Royal Greenwich Observatory, but by special arrangement quartz clocks have been installed. Three oscillators are now running.
(c) Hartland. The buildings of the Royal Greenwich Observatory at Hartland were officially handed over on 1956 October 5. They consist of:
1. Office block with dark-room, store and small workshop accommodation.
2. Non-magnetic observing building.
3. Non-magnetic recorder building.
4. Test hut No.1 to house the large coil (Braunbek) system, being designed to provide uniform magnetic fields suitable for tests on magnetic instruments.
5. Test hut No. 2 for general testing of instruments.
6. A small building to accommodate electronic equipment used in conjunction with the various coils.
The Report here presented refers to the period from 1957 April 1 to 1958 March 31 and exhibits the state of the Observatory on the last named day.
I. GROUNDS AND BUILDINGS.
Abinger. The Observatory Establishment was vacated and handed over to Admiralty Works Department on December 31.
Herstmonceux. The Equatorial Group has been completed and handed over, subject to relinquishment when necessary to deal with certain faults, mainly electrical. These are still recurrent, and restrict full installation and operation. The 28-inch Refractor, the 20-inch Isaac Roberts Reflector and the Astrographic Refractor have been erected, the declination axis and tube have been fitted to the polar axis of the Yapp 36-inch Reflector, and the 26-inch Refractor is approaching completion, but a continuous programme of work is not yet possible.
The West Block has been handed over to the Royal Greenwich Observatory. Departments have moved in and work is proceeding satisfactorily.
The Report here presented refers to the period from 1958 April 1 to 1959 March 31 and exhibits the state of the Observatory on the last named day.
The Royal Greenwich Observatory was visited by H. R. H. Prince Philip, Duke of Edinburgh, on 1958 November 14.
I. GROUNDS AND BUILDINGS.
Work is proceeding on the building of a suitable hut to house the Astrolabe.
All Domes and Shutters are at present in working order. For four weeks during November and December Dome E shutter mechanisms were completely dismantled and modified to remove excessive friction that was causing frequent failure. Replacement of broken rollers in the rotating mechanisms of all Domes has been carried out frequently.
During the last eight months observers reported faults on domes and shutters as follows:
Dome B 5 faults
D 1 “
E 8 “
F 8 "
The Report here presented refers to the period from 1959 April 1 to 1960 March 31 and exhibits the state of the Observatory on the last named day.
On 1959 May 21 the Lords Commissioners of the Admiralty approved in principle a joint recommendation by the Astronomer Royal and H.M. Astronomer at the Cape that the Royal Observatory at the Cape of Good Hope should be connected with the Royal Observatory at Herstmonceux, in the same manner as H.M. Nautical Almanac Office is connected. The many implications of this approval remain to be worked out in detail. It has been decided, however, to exhibit the report of H.M. Astronomer at the Cape to the Board of Visitors to the Royal Greenwich Observatory, and his report will be found next to this one. An immediate effect of the closer approach between the two Observatories has been an exchange of staff (see Section II). It is intended to discuss very fully the possibilities of joint programmes embracing observations in both hemispheres, and attention is being given to these currently.
In compliance with the Public Record Act, 1958, a catalogue has been prepared of all Royal Greenwich Observatory manuscripts for the period 1675-1881.
I. GROUNDS AND BUILDINGS.
All domes and shutters are in working order, except the shutters of Dome C which have seized up and are being overhauled.
The shutters of Dome B seized up during January, and the dome was out of action for three weeks while part of the shutter mechanism was removed and modified.
The shutter mechanisms of Dome A were dismantled and modified during March. During the year shutters failed to operate as follows:
Dome B on 3 occasions
" D " 2 "
" E " 6 “
“ F “ 9 “
In most cases operation was restored within a few hours. The total load on Royal Greenwich Observatory staff, caused by trouble with these domes, was about 215
man-days during the year, in addition to fairly heavy calls on the mechanical and electrical resident Chatham staff.
The original "Small Transit" pavilion has been successfully modified to accommodate the Danjon Astrolabe.
A public lavatory has been erected near the Works Pound, for the convenience of the numerous visitors on open afternoons.
A distant azimuth mark, for the Cooke Transit Circle, has been erected a little north of Pevensey Church. The light can be controlled from the Cooke pavilion, and telephonic communication is also available, to help in adjusting the beam.
The Observatory staff have erected a clubhouse just inside the West Gate.
The Report here presented refers to the period from 1960 April 1 to 1961 March 31 and exhibits the state of the Observatory on the last named day.
I. EQUIPMENT, BUILDINGS AND GROUNDS
The modification of the rotation and shutter mechanism, begun when the buildings were taken over from the contractor, has now been completed for all but one of the domes by the Observatory Workshop and resident Civil Engineering and Electrical Department staffs from the Navy Works Department. Since these modifications were completed in 1960 August, there have been no shutter faults of a mechanical nature.
The Cassegrain grating spectrograph for the 36-inch reflector has been nearly completed in the Observatory Workshop. The optics are being constructed by Grubb, Parsons Ltd.
A Coudé spectrograph for the 30-inch reflector is in the design stage in the workshop. Some of the modifications of the 30-inch reflector, that will be necessary for this spectrograph, have begun.
An integrating exposure meter has been constructed for the spectrograph of the 36-inch reflector by the electronics department. Modifications to the plate holders and slit mechanism of this spectrograph have also been made by the workshop.
A small spectrograph for use at the Newtonian focus of the 74-inch reflector has been designed and is partly constructed.
The electrical control circuits of the P.Z.T. have been completely redesigned and simplified. Automatic operation of the instrument is now possible.
Other activities of the electronic department and the workshop include the following: a cathode ray tube display has been fitted to the Iris diaphragm photometer; the main/battery operated oscillator installation used in the Time Department at Greenwich has been rehabilitated and sent to the Cape Observatory complete with quartz crystal units Nos. 94 and 447; a high stability power-supply and an integrator circuit have been developed for use in faint star photometry with the 74-inch reflector; a photoelectric photometer including a Lallemand infra-red multiplier was constructed and sent to the Cape Observatory; a motorized observing platform for the 28-inch refractor was constructed.
CAPE OF GOOD HOPE
Grubb Parsons report that the mechanical portion of the 40-inch reflector is nearing completion but they cannot yet predict when the instrument will be ready for delivery as there has been a delay in procuring the glass for the correcting system. The building for this telescope has been completed.
Dr. W. H. Steavenson has presented his 30-inch reflector, together with the framework of its dome, to the Observatory. This telescope, which was formerly mounted in Cambridge, is now at the Cape and will be mounted as soon as its building has been completed.
The new 80-inch f/10 astrometric lens manufactured by Taylor, Taylor and Hobson Ltd. has been mounted in a camera attached to the tube of the Victoria Telescope and has been used to obtain a series of plates covering the region of the Large Magellanic Cloud. The performance of this lens seems to be most satisfactory.
A 12-inch F/2 Ektar lens, which was presented to the Observatory a few years ago by Mr. A. G. F. Morrisby of Southern Rhodesia, has been mounted as a separate instrument on a small, reconditioned Dallmeyer Heliograph stand in the Tower Dome.
The reconditioning of the Reversible Transit Circle has been completed.
The Report here presented refers to the period from 1961 April 1 to 1962 March 31 and exhibits the state of the Observatory on the last-named day.
I. EXTERNAL RELATIONS
Inspection. In August, an Admiralty inspection team visited the Observatory and studied the grades of the staff engaged on different duties, and the complementing in general. Their recommendations have been received by the Astronomer Royal, and his comments have been submitted. Final decisions have still to be announced.
Longitude and the Ordnance Survey. As a result of an I.A.U. resolution, the Bureau de l'Heure undertook a comprehensive re-assessment of the adopted longitudes of all Time stations, with the two distinct aims of removing the more or less permanent corrections obtained every year for each observatory, and of referring the resulting unified system more reliably to Greenwich as its zero. The adopted longitudes of the Herstmonceux instruments were all made more easterly by 11 milliseconds, that assigned to the P. Z. T. being now lm 21s102 E. The changes were to be made in consultation with the observatories concerned; before agreeing to the new figure, the Observatory held consultations with the Ordnance Survey, who had used the old figure in their recently completed re-survey of the whole country, and who had also made special use of the Observatory's azimuth work. The Ordnance Survey were able to incorporate the new longitude. It has been in use for Time work (as the others have) from 1962 January 1.0, and the new figures will all be introduced together, in the Almanac, as soon as practicable.
Cape. The Cape Town Municipality has commenced work on the canalisation of the Black River, which lies to the east of the Royal Observatory, in connection with a new motorway which is being constructed. Although this work may assist in the effective drainage of the eastern portion of the grounds, the additional light to be expected from this and the other new major roads in the vicinity is causing some anxiety. Discussions are taking place with the Municipality to ascertain what degree of screening from the lights can be provided.
Publications. In previous years Royal Observatory Bulletins have been published by H.M. Stationery Office under a system in which different stages of the work (photolithography, stitching, binding etc.) have been the responsibility of different contractors. Serious handling delays caused by this system have now been obviated by placing a running contract with a single firm. A special arrangement with H. M. Stationery Office allows direct contact between the Observatory and the contractor: Dr. Hunter has been put in overall charge on the Observatory side, with Mr. Richards as assistant, and the average interval between despatch of copy and publication is now little more than three weeks. Achieving this result is well worth the relatively small increase of work involved in taking over all stages in production of copy, including layout of covers and title-pages and preparation of indexes.
Radioactive hazards. Representatives of various Ministries, and the Naval Medical Officer of Health (Portsmouth Command), have visited the Observatory and discussed on various occasions the handling of luminous paint residues which arise from broken dials and hands of watches sent for repair, and also the storage of replacements and of watches in general. The level of general radioactivity is low and is constantly monitored, but there has been some slight hazard from individual particles of paint, more especially where broken watches are first unpacked. It has now been agreed with the Air Ministry and with the Admiralty that all luminous watches with broken glass, dials, or hands shall be forwarded in disposable polythene bags, and a special unpacking cabinet with forced ventilation is being arranged for unpacking, as well as special washing facilities for the staff in question. Radioactive waste is disposed of by the official Admiralty procedure.
II. GROUNDS AND BUILDINGS
Some difficulty was experienced in opening the Equatorial Group shutters during the winter when temperatures were around freezing point. Representatives of the Admiralty Oil Laboratory, Brentford, have inspected the shutters and have recommended alternative lubricants. Dome C has been put at the disposal of Navy Works Department staff so that they can work out a satisfactory prototype method of re-hanging all dome shutters more conventionally.
The total time spent, during the year, on the domes and shutters was about 120 man days by Observatory Industrials, in addition to about 40 man hours by supervisory staff and some time by the Works Department electricians. The largest single item was a steady replacement of the dome rollers; Ferodo-tired rollers and phosphor-bronze ones both proved quite unsatisfactory, but the cast iron ones now being substituted are more in accord with standard dome practice and seem suitable.
The car park at the West Building has been extended to accommodate an additional 11 cars. Various road improvements have been carried out, including the construction of a lay-by on the east-west road and the widening of several corners.
A section of the West Building originally planned as storage space has been converted into offices and rating rooms for the Chronometer Department. Ventilated cupboards for the storage of radioactive luminescent materials have been fitted in these new rooms and in the Chronometer Workshop above.
Attention has been given to the brickwork over the windows on the east side of the West Building to prevent the ingress of rain-water.
Safety railings have been fitted at the side of the "bridge" over the main entrance to the Equatorial Group.
The floor of the Solar Office in the Castle has been renewed, and the electrical sub-mains in the Castle have been completely replaced.
The entire area of the Observatory grounds, apart from the fields let out to a tenant farmer, has been put in charge of the Forester, Mr. Pike, who has also been given an overriding responsibility for the gardens. The first five-year plan in the forestry work was completed early in 1962, and a plan for the next five years is now being drawn up. 54 acres have been cleared of bracken and scrub; rough oak, chestnut and sycamore from 8 acres were sold by tender. The cleared areas have been planted with about 11000 young hardwoods and softwoods, according to site and soil. Many of these were grown from seed. The large upper pond has also been drained and cleared out.
No further structural work has been done on the 40-inch telescope building, but a contract has been placed for the vacuum tank for the mirror aluminizing plant, which will be installed in advance of the telescope.
The Steavenson 30-inch reflector building has been completed and is now in use. It provides two much-needed additional offices below the dome floor. A further building to house the multiple refractor mounting that has been ordered is substantially complete. This building also provides suitable storage space for records and the Observatory's collection of photographic plates.
Sanction for the construction of a new house for the Chief Assistant was given late in the year. Designs have been prepared and the building should be completed by the end of 1962. A survey has been made to determine the most efficient use of the space that will be made available in the Main Building when the Chief Assistant moves into the new house.
The turret on the Main Building, which was provided in 1826 for a 25-foot zenith telescope, has been dismantled and replaced by a sky-light. This has greatly improved the natural lighting in the Entrance Hall.
In addition to normal routine maintenance, the Navy Works Department has carried out an extensive programme of improvements to the electrical supply system, including enlargement of the distribution sub-station and the replacement of inadequate cables. The old 25-line automatic telephone exchange has also been replaced by a new 40-line exchange of improved design. The maintenance programme included a major overhaul, the first on record, of the hydraulic rising floor system in the Victoria telescope dome.
The Report here presented refers to the period from 1962 April 1 to 1963 March 31 and exhibits the state of the Royal Greenwich Observatory and of the Cape Observatory on the last-named day.
I. EXTERNAL RELATIONS
Final agreement between the Astronomer Royal and the Admiralty inspection team referred to in the last Report was reached at a meeting in February. The findings of the team have been submitted to the Board of Admiralty and will be implemented when and insofar as they are approved.
In response to a request from the Royal Society, the Admiralty has agreed to help in the precise optical tracking of artificial satellites. Recruitment of the necessary staff to operate a tracking service has been authorized, and a kinetheodolite lent by the Royal Aircraft Establishment was delivered in March. It will be erected on an open site in the meteorological enclosure at Herstmonceux.
An observing site close to the R.T.C. at Herstmonceux has been occupied by two survey teams during the year. The 13th Field Squadron of the Royal Engineers and an Air Ministry survey party have made observations for the calibration of geodetic positions and azimuths by theodolite. Observatory time signals and the Pevensey azimuth mark have been utilized.
The end of the report year coincides with the transfer of the Navy Works Department (but not of Lands Branch) to the Ministry of Public Building and Works. Navy Works personnel at Herstmonceux will become Ministry staff, and (as an exception to the general rule) M. P. B. W. will undertake maintenance of mechanical equipment such as workshop machine tools as well as buildings at Herstmonceux.
The Board of Admiralty has acceded to the request of the U. S. Secretary of the Navy to lend Harrison's Timekeeper No. 4 to the U. S. Naval Observatory for a year, for exhibition in the new Simon Newcomb Laboratory at Washington. The Chronometer was recovered from the National Maritime Museum in September, overhauled in the Chronometer Workshop at Herstmonceux and transported across the Atlantic by naval vessel. Mr. W. Roseman, head of the workshop, accompanied the chronometer in the last stages of its journey from Norfolk, Va., was present when H.M. Ambassador in Washington formally handed it over, and subsequently installed it in the Laboratory and left it, going, on display.
The Lord Chancellor has exercised his powers under the Public Records Act, 1958 to designate the Royal Greenwich Observatory as the official repository of its own records and of those of the Cape Observatory. The Greenwich records from 1675 to 1881 have been arranged by régime and listed in the form prescribed by the Public Record Office. This work is being extended to 1910, and the Cape records will then be similarly dealt with. This unique collection covering the whole history of the oldest scientific establishment in the U.K. will then be available for the first time to students of the history of science.
II. GROUNDS AND BUILDINGS
The removal of the Chronometer Office from the Castle to the rating and storage rooms prepared in the West Building was completed in May.
Approximately five acres around the site of the Isaac Newton Telescope and the Mirror Transit Circle have been planted with young Scotch pine, beech and chestnut.
Exceptionally heavy snowfalls in January brought down 15 out of the 40 antennae of the "umbrella" aerial near the West Building and thereby caused gaps in the reception of certain time signals. Deep snowdrifts prevented access to the Equatorial Group for several days, and the prolonged period of low day and night temperatures in January and February severely tested the operation of the domes and shutters.
Dome C (now empty) has been used by Navy Works staff for experimental modification of the shutters and dome rotation gear. Weight-relieving rollers were fitted at top and bottom of one shutter, and means for lubricating the ram bearings have been added. The original stainless steel rollers on the outside track on which the dome rotates were replaced by rubber rollers. Tests of the effects of these modifications continue.
The electrical circuits for the shutters of all the equatorial domes have been so modified that in adverse conditions full power may be applied to each shutter in turn. During the exceptionally inclement winter it was frequently necessary, especially in the bigger domes, to use this facility: as a result, no observations were lost on account of shutter failure.
The 40-inch reflector dome and the multiple refractor house are both ready to receive their instruments. The stationery and record rooms incorporated in the base of the latter are both in use.
The new house for the Chief Assistant is virtually complete and will be occupied towards the end of April 1963.
The observation of faint objects from the present Observatory grounds is rapidly becoming impossible and an out-station will have to be found. The growing complex of Cape Town's new motor roads already lights up the Observatory on three sides, while the fourth will soon be lit by the Black River Boulevard which is nearing completion. The position is still further aggravated on two or three evenings a week in winter by floodlights recently fitted in a nearby football ground.
This Report has been drawn up in a different form from those of previous years, in an attempt to present a more readable account of the year's work separate from (whilst not excluding) detailed information that may be found of rather specialized interest.
The narrative Section (pp. 5 - 14) is intended to be read as a synoptic account of research activity at Herstmonceux and the Cape during the year. It makes no reference to routine work which, important though it is, changes little in nature from year to year. An abbreviated account of this latter work, and such details of the former as are unsuited to a narrative report, are contained in the Appendix (pp. 15 - 24).
GROUNDS AND BUILDINGS
The Herstmonceux domes and shutters have performed satisfactorily during the year. The shutters and dome rotation gear of the empty Dome C, experimentally modified last year by staff from Navy Works (now absorbed into the Ministry of Public Building and Works), have been tested regularly since, with satisfactory results. As the other domes are also operating satisfactorily it is difficult to form any conclusions about the relative effectiveness of the M.P.B.W. modifications and those carried out earlier by the Herstmonceux workshop staff.
Interference with observations of faint objects at the Cape by the brightness of the sky has been made worse by the opening of the Black River Boulevard with its powerful sodium lights. A special effort is to be made by the City Council to provide lamp shields for the lights that will line the new highway skirting the northern edge of the Observatory grounds; but no permanent solution to the problem can be expected on the present site.