Autobiography of Sir George Biddell Airy by George Biddell Airy (e reader for manga .TXT) 📕

have one common standard
among themselves : say Washington Observatory time. But this is only needed for the office-transactions between the railways; it may be kept perfectly private; never communicated to the public at all. And I should recommend this as the first step.

There will then be no difficulty in deducing, from these private Washington times, the accurate local times at those stations (whose longitude is supposed to be fairly well known, as a sailor with a sextant can determine one in a few hours) which the railway authorities may deem worthy of that honour; generally the termini of railways. Thus we shall have a series of bases of local time, of authoritative character, through the country.

Of such bases we have two, Greenwich and Dublin: and they are separated by a sea-voyage. In the U.S. of America there must be a greater number, and probably not so well separated. Still it is indispensable to adopt such a system of local centers.

No people in this world can be induced to use a reckoning which does not depend clearly upon the sun. In all civilized countries it depends (approximately) on the sun's meridian passage. Even the sailor on mid-ocean refers to that phenomenon. And the solar passage, with reasonable allowance, 20m. or 30m. one way or another, must be recognized in all time-arrangements as giving the fundamental time. The only practical way of doing this is, to adopt for a whole region the fundamental time of a center of that region.

And to this fundamental time, the local time of the railway, as now entering into all the concerns of life, must be adapted. A solicitor has an appointment to meet a client by railway; a physician to a consultation. How is this to be kept if the railway uses one time and every other act of life another?

There is one chain of circumstances which is almost peculiar--that of the line from New York to San Francisco. Here I would have two clocks at every station: those on the north side all shewing San Francisco time, and those on the south all shewing New York time. Every traveller's watch would then be available to the end of his journey.

A system, fundamentally such as I have sketched, would give little trouble, and may I think be adopted with advantage.

I am, Sir,
Your faithful servant,
G.B. AIRY.

Mr Edward Barrington.


1882

He returned from Playford on Jan. 17: his other movements during the year were as follows: from Apr. 27th to May 11th he was at Playford; and again from August 1st to 24th. From Oct. 9th to Nov. 1st he was travelling with his two unmarried daughters in the Lake District of Cumberland: the journey was by Furness and Coniston to Portinscale near Keswick; on Oct. 13th he fell and sprained his ankle, and his excursions for the rest of the time were mainly conducted by driving. Shortly after his return, on Nov. 11th, while walking alone on Blackheath, he was seized with a violent attack of illness, and lay helpless for some time before he was found and brought home: he seems however to have recovered to a great extent in the course of a day or two, and continued his Lunar Theory and other work as before. On June 22nd he made the following sad note, "This morning, died after a most painful illness my much-loved daughter-in-law, Anna Airy, daughter of Professor Listing of Goettingen, wife of my eldest son Wilfrid." In February he wrote out his reminiscences of the village of Playford during his boyhood.

In June he was much disturbed in mind on hearing of some important alterations made by the Astronomer Royal in the Collimators of the Transit Circle, and some correspondence ensued on the subject.--During the year he had much correspondence on the subject of the subsidences on Blackheath.

The following letter was written in reply to a gentleman who had asked whether it could be ascertained by calculation how long it is since the Glacial Period existed:

1882, July 4 .

SIR,

I should have much pleasure in fully answering your questions of July 3 if I were able to do so: but the subject really is very obscure.

(1) Though it is recognized that the glacial period (or periods) is late, I do not think that any one has ventured to fix upon a rude number of years since elapsed.

(2) We have no reason to think that the mean distance of the earth from the sun has sensibly altered. There have been changes in the eccentricity of the orbit (making the earth's distance from the sun less in one month and greater in the opposite month), but I do not perceive that this would explain glaciers.

(3) I consider it to be certain that the whole surface of the earth, at a very distant period, was very hot, that it has cooled gradually, and (theoretically and imperceptibly) is cooling still. The glaciers must be later than these hot times, and later than our last consolidated strata: but this is nearly all that I can say.

I am, Sir, Your obedient Servant,
G.B. AIRY.

James Alston, Esq.


1883

From May 2nd to 29th he was at Playford. From July 10th to 20th he was travelling in South Wales with his daughters.--From Oct. 10th to Nov. 10th he was at Playford.--Between Nov. 20th of this year and Jan. 4th of the year 1884, he sat several times to Mr John Collier for his portrait: the picture was exhibited in the Academy of 1884; it is a most successful and excellent likeness.

Throughout the year he was very busy with the Numerical Lunar Theory.--In March he was officially asked to accept the office of Visitor of the Royal Observatory, which he accepted, and in this capacity attended at the Annual Visitation on June 2nd, and addressed a Memorandum to the Visitors on the progress of his Lunar Theory.--On March 12th he published in several newspapers a statement in opposition to the proposed Braithwaite and Buttermere Railway, which he considered would be injurious to the Lake District, in which he took so deep an interest.--In May he communicated to "The Observatory" a statement of his objections to a Theory advanced by Mr Stone (then President of the Royal Astronomical Society) to account for the recognized inequality in the Mean Motion of the Moon. This Theory, on a subject to which Airy had given his incessant attention for so many years, would naturally receive his careful attention and criticism, and it attracted much general notice at the time.--In December he wrote to the Secretary of the Royal Astronomical Society his opinion as to the award of the Medal of the Society. In this letter he stated the principles which guided him as follows: "I have always maintained that the award of the Medal ought to be guided mainly by the originality of communications: that one advance in a new direction ought in our decision to outweigh any mass of work in a routine already established: and that, in any case, scientific utility as distinguished from mere elegance is indispensable."--In July Lieut. Pinheiro of the Brazilian Navy called with an autograph letter of introduction from the Emperor of Brazil. The Lieutenant desired to make himself acquainted with the English system of Lighthouses and Meteorology, and Airy took much trouble in providing him with introductions through which he received every facility for the thorough accomplishment of his object.--On Oct. 8th he forwarded to Prof. Cayley proofs of Euclid's Propositions I. 47 and III. 35 with the following remarks: "I place on the other side the propositions which may be substituted (with knowledge of Euclid's VI. book) for the two celebrated propositions of the geometrical books. They leave on my mind no doubt whatever that they were invented as proofs by ratios, and that they were then violently expanded into cumbrous geometrical proofs."--On June 28th he declined to sign a memorial asking for the interment of Mr Spottiswoode in Westminster Abbey, stating as his reason, "I take it, that interment possessing such a public character is a public recognition of benefits, political, literary, or philosophical, whose effects will be great and durable. Now I doubt whether it can be stated that Mr Spottiswoode had conferred such benefits on Society. "But he adds at length his cordial recognition of Mr Spottiswoode's scientific services.--Throughout his life Airy was a regular attendant at church, and took much interest in the conduct of the Church services. In October of this year he wrote a long letter to the Vicar of Greenwich on various points, in which occurs the following paragraph: "But there is one matter in the present form of the Church Service, on which my feeling is very strong, namely the (so-called, I believe) Choral Service, in the Confession, the Prayer, and the Creed. I have long listened with veneration to our noble Liturgy, and I have always been struck with the deep personally religious feeling which pervades it, especially those parts of it which are for 'The People.' And an earnest Priest, earnestly pressing these parts by his vocal example on the notice of the People, can scarcely fail to excite a corresponding earnestness in them. All this is totally lost in the choral system. For a venerable persuasion there is substituted a rude irreverential confusion of voices; for an earnest acceptance of the form offered by the Priest there is substituted--in my feeling at least--a weary waiting for the end of an unmeaning form." He also objected much to singing the responses to the Commandments.


1884

From Apr. 29th to May 30th he was at Playford, concluding his Journal there with the note "So ends a pleasant Vacation."--On June 11th he went to Cambridge and attended the Trinity College Commemoration Service, and dined in Hall.--From Aug. 14th to Sept. 11th he was at Playford.--On Sept. 26th he made an expedition to Guildford and Farnham.--During this year he was closely engaged on the Numerical Lunar Theory, and for relaxation was reading theology and sundry books of the Old Testament.

On June 7th he attended at the Visitation of the Royal Observatory.--In a letter written in April to Lt.-Col. Marindin, R.A., on the subject of wind pressure there occurs the following remark: "When the heavy gusts come on, the wind is blowing in directions changing rapidly, but limited in extent. My conclusion is that in arches of small extent (as in the Tay Bridge) every thing must be calculated for full pressure; but in