I am, my Lord Duke,
Your Grace’s very faithful servant,
G.B. AIRY.
His Grace
The Duke of Devonshire.
* * * * *
There were in all 19 Honorary Degrees of Doctor of Laws conferred on the 9th of June, including men of such eminence as Armstrong, Faraday, and Fairbairn.
1863
In this year there were several schemes for a Railway through the lower part of Greenwich Park, the most important being the scheme of the London, Chatham and Dover Railway Company. In reference to this scheme the Report to the Visitors states “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 ensure ruin to the Observatory.”—“The meridional observations of Mars in the Autumn of 1862 have been compared with those made at the Observatory of Williamstown, near Melbourne, Australia, and they give for mean solar parallax the value 8.932”, exceeding the received value by about 1/24th part. (A value nearly identical with this 8.93” has also been found by comparing the Pulkowa and Cape of Good Hope Observations.)”—“The results of the new Dip-Instrument in 1861 and 1862 appear to give a firm foundation for speculations on the state and change of the dip. As a general result, I may state as probable that the value of dip in the middle of 1843 was about 69 deg.1’, and in the middle of 1862 about 68 deg.11’. The decrease of dip appears to be more rapid in the second half of this interval than in the first; the dip at beginning of 1853 being about 68 deg.44’.”—With reference to the re-determination of the longitude of Valencia, it is stated that “The concluded longitude agrees almost exactly with that determined by the transmission of chronometers in 1844; and entitles us to believe that the longitudes of Kingstown and Liverpool, steps in the chronometer conveyance, were determined with equal accuracy.”—“The computations, for inferring the direction and amount of movement of the Solar System in space from the observed proper motions of 1167 stars, have been completed. The result is, that the Sun is moving towards a point, R.A. 264 deg., N.P.D. 65 deg. (not very different from Sir W. Herschel’s, but depending much in N.P.D. on the accuracy of Bradley’s quadrant observations), and that its annual motion subtends, at the distance of a star of the first magnitude, the angle 0.4”. But the comparison, of the sum of squares of apparent proper motions uncorrected, with the sum of squares of apparent proper motions corrected for motion of Sun, shews so small an advance in the explanation of the star’s apparent movements as to throw great doubt on the certainty of results; the sum of squares being diminished by only 1/25th part.”—“I had been writing strongly to Maclear on the delays in publishing both the geodetic work and the Star Catalogue at the Cape of Good Hope: he resolves to go on with these works. In December I am still very urgent about the geodesy.”