Autobiography of Sir George Biddell Airy - George Biddell Airy (android based ebook reader txt) 📗

our original system of independent wires (formerly to Croydon and Dartford).--The new Azimuth-mark (for the Altazimuth), upon the parapet of the Naval College, is found to be perfectly satisfactory as regards both steadiness and visibility. The observations of a low star for zero of azimuth have been omitted since the beginning of 1881; the mark, in combination with a high star, appearing to give all that is necessary for this purpose.--All the instruments have suffered from the congealing of the oil during the severe weather of the past winter, and very thorough cleaning of all the moving parts has been necessary.--The Solar Eclipse of 1880, Dec. 31, was well observed. The first contact was observed by four observers and the last contact by two. The computations for the observations have been exceptionally heavy, from the circumstance that the Sun was very low (86 deg. 14' Z.D. at the last observation) and that it has therefore been necessary to compute the refraction with great accuracy, involving the calculation of the zenith distance for every observation. And besides this, eighty-six separate computations of the tabular R.A. and N.P.D. of cusps have been required.--Amongst other interesting spectroscopic observations of the Sun, a remarkable spectrum of a sun-spot shewing 17 strong black lines or bands, each as broad as b_1, in the solar spectrum, was observed on 1880, Nov. 27 and 29. These bands to which there is nothing corresponding in the Solar Spectrum (except some very faint lines) have also been subsequently remarked in the spectrum of several spots.--The Police Ship 'Royalist' (which was injured by a collision in 1879 and had been laid up in dock) has not been again moored in the river, and the series of observations of the temperature of the Thames is thus terminated. --Part of the month of January 1881 was, as regards cold, especially severe. The mean temperature of the period January 12 to 26 (15 days) was only 24.2 deg., or 14.7 deg. below the average; the temperature fell below 20 deg. on 10 days, and rose above the freezing point only on 3 days. The highest temperature in this period was 35.3 deg., the lowest 12.7 deg.. On January 17th (while staying at Playford) my son Hubert and I noticed an almost imperceptible movement in the upper clouds from the South-East. On that night began the terrible easterly gale, accompanied with much snow, which lasted to the night of the 18th. The limiting pressure of 50 lbs. on the square foot of Osler's Anemometer was twice exceeded during this storm.--With respect to the Diurnal Inequalities of Magnetic Horizontal Force: Assuming it to be certain that they originate from the Sun's power, not immediately, but mediately through his action on the Earth, it appears to me (as I suggested long ago) that they are the effects of the attraction of the red end or north end of the needle by the heated portions of our globe, especially by the heated sea, whose effect appears to predominate greatly over that of the land. I do not say that everything is thus made perfectly clear, but I think that the leading phenomena may be thus explained. And this is almost necessarily the way of beginning a science.--In the first few years after the strict and systematic examination of competitive chronometers, beginning with 1856, the accuracy of chronometers was greatly increased. For many years past it has been nearly stationary. I interpret this as shewing that the effects of bad workmanship are almost eliminated, and that future improvement must be sought in change of some points of construction.--Referring to the Transit of Venus in 1874, the printing of all sections of the Observations, with specimens of the printed forms employed, and remarks on the photographic operations, is very nearly completed. An Introduction is begun in manuscript. I am in correspondence with the Commission which is entrusted with the arrangements for observation of the Transit of 1882.--The Numerical Lunar Theory has been much interrupted by the pressure of the Transit of Venus work and other business."--In his Report to the Board of Visitors (his 46th and last), Airy remarks that it would be a fitting opportunity for the expression of his views on the general objects of the Observatory, and on the duties which they impose on all who are actively concerned in its conduct. And this he proceeds to do in very considerable detail.--On May 5th he wrote to Lord Northbrook (First Lord of the Admiralty) and to Mr Gladstone to resign his post of Astronomer Royal. From time to time he was engaged on the subject of a house for his future residence, and finally took a lease of the White House at the top of Croom's Hill, just outside one of the gates of Greenwich Park. On the 15th of August he formally resigned his office to Mr W.H.M. Christie, who had been appointed to succeed him as Astronomer Royal, and removed to the White House on the next day, August 16th.

His holiday movements in the portion of the year up to August 16th consisted in his winter visit to Playford, from which he returned on Jan. 24th: and a subsequent visit to Playford from June 7th to 18th.

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The following correspondence relating to Airy's retirement from office testifies in a remarkable manner to the estimation in which his services were held, and to the good feeling which subsisted between him and his official superiors.


10, DOWNING STREET, WHITEHALL,
_June 6, 1881_.

DEAR SIR GEORGE AIRY,

I cannot receive the announcement of your resignation, which you have just conveyed to me, without expressing my strong sense of the distinction you have conferred upon the office of Astronomer Royal, and of the difficulty of supplying your place with a person of equal eminence. Let me add the expression of my best wishes for the full enjoyment of your retirement from responsibility.

I remain, dear Sir George Airy,
Faithfully yours,
W.E. GLADSTONE.

* * * * *

ADMIRALTY,
_June 10th, 1881_.

SIR,

I am commanded by my Lords Commissioners of the Admiralty to acknowledge the receipt of your letter of the 4th instant, intimating your desire to retire on the 15th August next from the office of Astronomer Royal.

2. In reply I am to acquaint you that your wishes in this matter have been communicated to the Prime Minister, and that the further necessary official intimation will in due course be made to the Treasury.

3. At the same time I am instructed by their Lordships to convey to you the expression of their high appreciation of the remarkably able and gifted manner, combined with unwearied diligence and devotion to the Public Service (especially as regards the Department of the State over which they preside), in which you have performed the duties of Astronomer Royal throughout the long period of forty-five years.

4. I am further to add that their Lordships cannot allow the present opportunity to pass without giving expression to their sense of the loss which the Public Service must sustain by your retirement, and to the hope that you may long enjoy the rest to which you are so justly entitled.

I am, Sir,
Your obedient Servant,
ROBERT HALL.

_Sir G. B. Airy, K.C.B.
&c., &c.,
Royal Observatory, Greenwich._

* * * * *

ADMIRALTY,
_28th June, 1881_.

SIR,

My Lords Commissioners of the Admiralty have much pleasure in transmitting copy of a resolution passed by the Board of Visitors of the Royal Observatory on the 4th June last, bearing testimony to the valuable services you have rendered to Astronomy, to Navigation, and the allied Sciences throughout the long period during which you have presided over the Royal Observatory.

I am, Sir,
Your obedient Servant,
ROBERT HALL.

_Sir George Biddell Airy, K.C.B.
&c., &c., &c.,
Royal Observatory, Greenwich._


"The Astronomer Royal (Sir George B. Airy) having announced his intention of shortly retiring from his position at the Royal Observatory, the following resolution proposed by Professor J. C. Adams, and seconded by Professor G. G. Stokes, was then unanimously adopted and ordered to be recorded in the Minutes of the Proceedings.

"The Board having heard from the Astronomer Royal that he proposes to terminate his connection with the Observatory on the 15th of August next, desire to record in the most emphatic manner their sense of the eminent services which he has rendered to Astronomy, to Navigation and the allied Sciences, throughout the long period of 45 years during which he has presided over the Royal Observatory.

"They consider that during that time he has not only maintained but has greatly extended the ancient reputation of the Institution, and they believe that the Astronomical and other work which has been carried on in it