|Date:||1829, with 1830 corrections|
|Author:||1829 article, anonymous. Corrections by (JH) John Henry – Assistant at the Observatory since 1811. Henry, also went by the name of Belville.|
|Title:||Royal Observatory, Greenwich|
|About:||Published in The Mirror of Literature, Amusement and Instruction (J. Limbird, London), this account appeared in Vol. XIV, No. 404, pp.401 & 402 on Saturday 12 Dec 1829. The account was somewhat out dated, with significant amounts that appear to have been directly copied from the 1798 account written by Thomas Evans. Writing to the Editor, the Observatory's Second Assistant, John Henry wrote: "... I perceive you have availed yourself of an account which is rather imperfect for the present day. I will, therefore, with your leave, briefly state the additions and improvements recently made in that building." Henry's letter was published in Vol XV, No. 413, p.83 on Saturday 30 Jan 1830. On the matter of plagarism, Dick's account published in 1845 is remarkably similar.
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The Royal Observatory, Greenwich.
The first stone of this Observatory was laid by Flamstead, on the 10th of August, 1675. It stands 160 feet above low-water mark, and principally consists of two separate buildings: the first contains three rooms on the ground-floor – viz. the transit-room, towards the east, the quadrant-room, towards the west, and the assistant's sitting and calculating-room, in the middle; above which is his bed-room, the latter being furnished with sliding shutters in the roof. In the transit-room is an eight-feet transit-instrument, with an axis of three feet, resting on two piers of stone: this was made by Bird, but has been much improved by Dolland, Troughton, and others. Near it is a curious transit-clock, made by Graham, but greatly improved by Earnshaw, who so simplified the train as to exclude two or three wheels, and also added cross-braces to the gridiron-pendulum, by which an error of a second per day, arising from its sudden starts, was corrected. The quadrant-room has a stone pier in the middle, running north and south, having on its east face a mural-quadrant, of eight feet radius, made by Bird, in 1749, by which observations are made on the southern quarter of the meridian, through an opening in the roof three feet wide, produced by means of two sliding shutters; on its west face is another eight-feet mural quadrant, with an iron frame, and an arch of brass, made by Graham, in 1725: this is applied to the north quarter of the meridian. In the same apartment is the famous zenith-sector, twelve feet in length, with which Dr. Bradley, at Wanstead, and at Kew, made those observations which led to the discovery of the aberration and nutation: here also is Dr. Hooke's reflecting telescope, and three telescopes [time-keepers] by Harrison. On the south side of this room is a small building, for observing the eclipses of Jupiter's satellites, occultations, &c., with sliding shutters at the roof and sides, to view any portion of the hemisphere, from the prime verticle down to the southern horizon: this contains a forty-inch achromatic, by the inventor, Mr. John Dolland, with a triple object-glass, a most perfect instrument of its kind; and a five-feet achromatic, by John and Peter Dolland, his sons. Here, likewise, are a two-feet reflecting-telescope (the metals of which were ground by the Rev. Mr. Edwards), and a six-feet reflector, by Dr. Herschell.
The lower part of the house serves merely for a habitation; but above is a large octagonal room, which, being now seldom wanted for astronomical purposes, is used as a repository for such instruments as are too large to be generally employed in the apartments first described, or for old instruments, which modern improvements have superseded. Among the former is a most excellent ten-feet achromatic, by the present Mr. Dolland, and a six-feet reflector, by Short, with a clock to be used with them. In the latter class, besides many curious and original articles, which are deposited in boxes and cupboards, is the first transit instrument that was, probably, ever made, having the telescope near one end of the axis; and two long telescopes with square wooden tubes, of very ancient date. Here, likewise, is the library, which is stored with scarce and curious old astronomical works, including Dr. Halley's original observations, and Captain Cook's Journals. Good busts of Flamstead and Newton, on pedestals, ornament this apartment; and in one corner is a dark narrow staircase, leading to the leads above, whence the prospect is uncommonly grand; and to render the pleasure more complete, there is, in the western turret, a camera obscura, of unrivalled excellence, by which all the surrounding objects, both movable and immovable, are beautifully represented in their own natural colours, on a concave table of plaster of Paris, about three feet in diameter.
On the north side of the Observatory are two small buildings, covered with hemispherical sliding domes, in each of which is an equatorial sector, made by Sisson, and a clock, by Arnold, with a three-barred pendulum, which are seldom used but for observing comets. The celebrated Dry-well, which was made to observe the earth's annual parallax, and for seeing the stars in the day-time, is situated near the south-east corner of the garden, behind the Observatory, but has been arched over, the great improvements in telescopes having long rendered it unnecessary. It contains a stone staircase, winding from the top to the bottom.
The Rev. John Flamstead, Dr. Halley, Dr. Bradley, Dr. Bliss, Dr. Nev. Maskelyne, and John Pond, Esq. have been the successive astronomers-royal since the foundation of this edifice.
[From 30 Jan 1830 edition]
ROYAL OBSERVATORY, GREENWICH.
(To the Editor of the Mirror.)
IN your description of the Royal Observatory, at Greenwich, in the Mirror (No. 404), I perceive you have availed yourself of an account which is rather imperfect for the present day. I will, therefore, with your leave, briefly state the additions and improvements recently made in that building.
In the first place, adjoining the transit-room eastward, is the circle-room, containing two mural circles, each three feet radius. The one facing the east, and made by Troughton, is divided on platina, and is furnished with six microscopes, attached to the stone pier, for reading off the observations to the tenth part of a second of space; and a fine achromatic telescope, six feet focal length, and furnished with a micrometer, is fixed to the circle. The other circle, which faces the west, and is constructed in every respect like the former, is divided on gold, by T. Jones, of Charing-cross, and is likewise furnished with a six-feet telescope and six microscopes.
These two instruments require two observers, as they are always used simultaneously – together with a third, who presides at the transit instrument. – There is also a noble telescope, ten feet focal length, and five inches aperture, made by Troughton; the object-glass by Dolland. The clock employed for the right ascensions, is one of Hardy's, of unrivalled workmanship, and cost £200.
The old eight-feet transit is now suspended upon the wall, by the side of Flamstead's.
Beyond the circle-room is the library, containing a large collection of valuable books, connected with astronomy and mathematics; and the chronometer-room, wherein are deposited the marine time-keepers, belonging to the Admiralty, and the trial chronometers, which are placed there, pursuant to the direction, of the late Board of Longitude – the best going watch being entitled, after a year's rate, to a reward of £300, and the second best £200.
In the quadrant-room, besides the two quadrants, hang, the large zenith sector, by which Dr. Bradley discovered the aberration of light. It must be stated, however, that the accuracy of the mural circles has superseded the use of the' quadrants and the zenith sector.
In the eastern dome, the old equatorial sector, by Sisson, has long since been removed, and a fine instrument (equatorial), by Ramsden, substituted. This invaluable instrument was presented to the Observatory in the year 1811, by Sir George Shuckburgh Evelyn, Bart.
The instruments in the great octagon-room consist chiefly of telescopes; a ten feet reflector, and seven-feet reflector, both by Herschel; together with clocks, pendulums, theodolites, and a variety of smaller instruments, &c.
The observations are now published every quarter, and are made under the direction of the Astronomer Royal, who superintends the whole. There are likewise six assistants, on regular salaries, appointed, to take the observations, and make the computations necessary, for the final results. They relieve each other in their respective duties, that no interruption may take place, in fine clear evenings and nights, during the observations.
Assistant at the Royal Observatory, Royal Observatory, Greenwich.