The intention of this page is to give details of all the solar eclipses observed from Greenwich in the time of Airy. This will take some time to complete, as a total of 13 eclipses are thought to have been observed.
This eclipse was observed by Airy in Turin in Italy. Click here to read more.
When the Nautical Almanac for the year 1847 was published in 1843, it showed that the Observatory was right on the edge of the predicted path of annularity of the annular solar eclipse of 9 October.
The annular phase was predicted to be visible from much of southern England, so in addition to producing a global map showing the path of the eclipse, the Nautical Almanac Office also produced a detailed map showing those parts of Ireland and Great Britain where the eclipse would be annular. This was constructed by calculating the longitude and latitude of nine points on the northern limit of annularity, eight points on the southern limit and nineteen points on the central line. For more details see pp.543-548 of the Almanac, where it should be noted that the timings are given in terms of the astronomical day (which began at midday) rather than the civil day (which began at midnight).
Map showing the areas of England and Ireland where the eclipse was predicted to be annular. From a copy of the Nautical Almanac and Astronomical Ephemeris for the year 1847 belonging to Oxford University. Digitised by Google
The Almanac gave the following detailed predictions for Greenwich:
Civil time & date |
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Partial phase begins | 06h 14.2m on 9 October (18h 14.2m on 8 October astronomical time) |
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Annular phase begins | 07h 26.7m | |
Greatest phase | 07h 27.3m | |
Annular phase ends | 07h 27.9m | |
Partial phase ends | 08h 48.3m |
In his 1848 Annual Report to the Board of Visitors, Airy wrote (quoting the wrong date):
'The northern boundary of annularity in the Solar Eclipse of 1847, October 7, passed so near to Greenwich, that it was doubtful whether the Eclipse would or would not be annular at the Royal Observatory. I determined, therefore, for the purpose of carefully observing all the phenomena of close contact, and for fixing with great precision the boundary of the annular track, to observe it at several stations north and south of Greenwich. Availing myself liberally of the assistance of astronomical friends, I equipped in the most complete manner, seven stations besides the Royal Observatory: [from north to south they were] at Chingford, Walthamstow, Stratford, BlackwalI, Lewisham, Lewisham-Southend, and Hayes. At none of them, however, was the Eclipse seen for five minutes, and at none at all in its annular phase.'
It is thought that the Observer at Chingford was probably Richard Hodgson and that at Hayes the Rev. Thomas Hussey (RGO6/112 may confirm this). Exactly what Airy meant in his last sentence is unclear (RGO6/112 may clarify). Was the annular phase not seen because of the weather, or was it because all the stations were in fact outside the zone of annularity? Espernak's predictions suggest the northern limit of annularity was about 1¼ miles to the south Hussey's home in Hayes.
Espernak's calculations give the following predictions for the eclipse when viewed from Greeenwich
Civil time on 9 October |
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Partial phase begins | 06:16 (already in progress at sunrise) |
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Greatest phase |
07:27:53 |
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Partial phase ends | 08:48:55 | |
Eclipse Magnitude | 0.917 | |
Eclipse Obscuration | 0.845 |
This eclipse was observed in Christiana and Christianstadt in Sweden. Click here to read more.
Having been thwarted by circumstances in his efforts to establish the boundary of annularity during the annular solar eclipse of 9 October 1847, Airy was presented with a second bite of the cherry in 1858 when another annular eclipse occurred that was visible from England.
As was the case in 1847 as well as producing a global map showing the path of the eclipse, the Nautical Almanac Office also produced a detailed map showing the central line of the eclipse across England. This was constructed by calculating the longitude and latitude of nineteen points on the central line. Unlike 1847, these came with the warning that 'they are accurate only on the assumption that the Moon's tabular places are exact, ... '. Also, unlike 1847, no attempt was made to plot the northern and southern limits of annularity. For more details see pp.464-471 of the Almanac, where it should be noted that the timings are given in terms of the astronomical day (which began at midday) rather than the civil day (which began at midnight).
Map showing the predicted central path of the eclipse across England. From a copy of the Nautical Almanac and Astronomical Ephemeris for the year 1858 belonging to the University of Miichigan. Digitised by Google
The Almanac gave the following detailed predictions for Greenwich:
Civil time on 15 March |
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Partial phase begins | 11h 41.4m (23h 41.4m on 14 March astronomical time) |
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Greatest phase | 13h 00.4m (01h 00.4m on 15 March astronomical time) | |
Partial phase ends | 14h 17.4m |
In his 1858 Annual Report to the Board of Visitors, Airy wrote:
'The excessively bad weather on the day of the Solar Eclipse of 1858, March 15, made it impossible to take at Greenwich more than two or three measures of North Polar Distance of cusps scarcely worth recording. With the assistance of the Rev. George Fisher and John Riddell, Esq., of the Greenwich Hospital Schools, and of six skilful and intelligent lads of the Upper School; and aided by the cordial hospitality of William Blower, Esq., of Bedford; Charles Simpson, Esq., of Harrowden, near Wellingborough; and W. De Capell Brooke, Esq., of Market Harborough; I organized three well-appointed observatories (one nearly on the central track, and one at each side of it), equipped for the purpose of making numerous measures of the distance of the cusps, by means of which the apparent correction to the diameters of the Sun and Moon, and the absolute correction to the elements of the Moon's path, would have been found with great accuracy. Only at Bedford, however, were a few observations obtained. In regard to all its real objects, the expedition failed entirely.'
The observations at Greenwich were made with the Shuckburgh Equatorial and the clock Arnold 1 in the North Dome (the former eastern summerhouse) and published in the 1858 volume of Greenwich Observations. The observations were published under the title:
The name of the observer was not published.
Espernak's calculations give the following predictions for the eclipse when viewed from Greenwich:
Civil time on 15 March |
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Partial phase begins | 11:41:47 |
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Greatest phase |
13:00:39 |
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Partial phase ends | 14:17:35 | |
Eclipse Magnitude | 0.974 | |
Eclipse Obscuration | 0.996 |
Click here to view Espernak's maps showing the path of the eclipse.
This eclipse was viewed both at Greenwich (as a partial eclipse) and in Spain (as a total eclipse). Click here to read more about the expedition to Spain.
This eclipse was viewed both at Greenwich (as a partial eclipse) and in Oran (as a total eclipse. Click here to read more about the expedition to Oran.
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