Autobiography of Sir George Biddell Airy, George Biddell Airy [best english books to read for beginners txt] 📗

disturbance of Uranus, and arrived at conclusions not very different from those of Adams. I wrote from Ely on July 9th to Challis, begging him, as in possession of the largest telescope in England, to sweep for the planet, and suggesting a plan. I received information of its recognition by Galle, when I was visiting Hansen at Gotha. For further official history, see my communications to the Royal Astronomical Society, and for private history see the papers in the Royal Observatory. I was abused most savagely both by English and French."

The Report to the Visitors contains an interesting account of the Great Lunar Reductions, from which the following passage is extracted: "Of the Third Section, containing the comparison of Observed Places with Tabular Places, three sheets are printed, from 1750 to 1756. This comparison, it is to be observed, does not contain a simple comparison of places, but contains also the coefficients of the various changes in the moon's place depending on changes in the elements.... The process for the correction of the elements by means of these comparisons is now going on: and the extent of this work, even after so much has been prepared, almost exceeds belief. For the longitude, ten columns are added in groups, formed in thirteen different ways, each different way having on the average about nine hundred groups. For the ecliptic polar distance, five columns are added in groups, formed in seven different ways, each different way having on the average about nine hundred groups. Thus it will appear that there are not fewer than 150,000 additions of columns of figures. This part of the work is not only completed but is verified, so that the books of comparison of Observed and Tabular Places are, as regards this work, completely cleared out. The next step is to take the means of these groups, a process which is now in hand: it will be followed by the formation and solution of the equations on which the corrections of the elements depend."

The following remarks, extracted from the Report to the Visitors, with respect to the instrumental equipment of the Observatory, embody the views of the Astronomer Royal at this time: "The utmost change, which I contemplate as likely to occur in many years, in regard to our meridional instruments, is the substitution of instruments of the same class carrying telescopes of larger aperture. The only instrument which, as I think, may possibly be called for by the demands of the astronomer or the astronomical public, is a telescope of the largest size, for the observation of faint nebulae and minute double stars. Whether the addition of such an instrument to our apparatus would be an advantage, is, in my opinion, not free from doubt. The line of conduct for the Observatory is sufficiently well traced; there can be no doubt that our primary objects ought to be the accurate determination of places of the fundamental Stars, the Sun, the Planets, and, above all, the Moon. Any addition whatever to our powers or our instrumental luxuries, which should tend to withdraw our energies from these objects, would be a misfortune to the Observatory."

Of private history: "In March I visited Prof. Sedgwick at Norwich.--On Mar. 28th the 'Sir Henry Pottinger' was launched from Fairbairn's Yard on the Isle of Dogs, where I was thrown down and dislocated my right thumb.--From Apr. 10th to 15th I was at Playford.--On June 10th Prof. Hansen arrived, and stayed with me to July 4th.--From July 6th to 10th I was visiting Dean Peacock at Ely.--From July 23rd to 29th I was at Playford, where for the first time I lodged in my own cottage. I had bought it some time before, and my sister had superintended alterations and the addition of a room. I was much pleased thus to be connected with the happy scenes of my youth.--From Aug. 10th to Oct. 11th I was with my wife and her sister Elizabeth Smith on the Continent. We stayed for some time at Wiesbaden, as my nerves were shaken by the work on the Railway Gauge Commission, and I wanted the Wiesbaden waters. We visited various places in Germany, and made a 10-days' excursion among the Swiss Mountains. At Gotha we lodged with Prof. Hansen for three days; and it was while staying here that I heard from Prof. Encke (on Sept. 29th) that Galle had discovered the expected planet. We visited Gauss at Goettingen and Miss Caroline Herschel at Hannover. We had a very bad passage from Hamburgh to London, lasting five days: a crank-pin broke and had to be repaired: after four days our sea-sickness had gone off, during the gale--a valuable discovery for me, as I never afterwards feared sea-sickness.--On Dec. 22nd I attended the celebration of the 300th anniversary of Trinity College."

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The following extracts relating to the engines of the "Janus" are taken from letters to his wife dated from Portsmouth, Jan. 6th and 7th, 1846:

As soon as possible we repaired to the Dock Yard and presented ourselves to the Admiral Superintendant--Admiral Hyde Parker (not Sir Hyde Parker). Found that the "Janus" had not arrived: the Admiral Superintendant (who does not spare a hard word) expressing himself curiously thereon. But he had got the proper orders from the Admiralty relating to me: so he immediately sent for Mr Taplin, the superintendant of machinery: and we went off to see the small engine of Lord D--d's construction which is working some pumps and other machinery in the yard. It was kept at work a little longer than usual for us to see it. And I have no hesitation in saying that it was working extremely well. It had not been opened in any way for half a year, and not for repair or packing for a much longer time.... This morning we went to the Dock Yard, and on entering the engine house there was Shirreff, and Lord D--d soon appeared. The "Janus" had come to anchor at Spithead late last night, and had entered the harbour this morning. Blowing weather on Saturday night. We had the engine pretty well pulled to pieces, and sat contemplating her a long time. Before this Denison had come to us. We then went on board the "Janus" with Shirreff but not with Lord D--d. The engines were still hot, and so they were turned backwards a little for my edification. (This was convenient because, the vessel being moored by her head, she could thus strain backwards without doing mischief.) The vacuum not good. Then, after a luncheon on board, it was agreed to run out a little way. But the engines absolutely stuck fast, and would not stir a bit. This I considered a perfect Godsend. So the paddle-wheels (at my desire) were lashed fast, and we are to see her opened to-morrow morning.

This morning (Jan. 7th) we all went off to the "Janus," where we expected to find the end of the cylinder (where we believe yesterday's block to have taken place) withdrawn. But it was not near it. After a great many bolts were drawn, it was discovered that one bolt could not be drawn, and in order to get room for working at it, it was necessary to take off the end of the other cylinder. And such a job! Three pulley hooks were broken in my sight, and I believe some out of my sight. However this auxiliary end was at last got off: and the people began to act on the refractory bolt. But by this time it was getting dark and the men were leaving the dockyard, so I left, arranging that what they could do in preparation for me might be done in good time to-morrow morning.


1847

"On Nov. 13th I circulated an Address, proposing to discontinue the use of the Zenith Tube, because it had been found by a long course of comparative trials that the Zenith Tube was not more accurate than the Mural Circle. The Address stated that 'This want of superior efficiency of the Zenith Tube (which, considered in reference to the expectations that had been formed of its accuracy, must be estimated as a positive failure) is probably due to two circumstances. One is, the use of a plumb-line; which appears to be affected with various ill-understood causes of unsteadiness. The other is, the insuperable difficulty of ventilating the room in which the instrument is mounted.'--On December 20th I circulated an Address, proposing a Transit Circle, with telescope of 8 inches aperture. The Address states as follows: 'The clear aperture of the Object-Glass of our Transit Instrument is very nearly 5 inches, that of our Mural Circle is very nearly 4 inches.'--I had been requested by the Master-General of Ordnance (I think) to examine Candidates for a Mastership in Woolwich Academy, and I was employed on it in February and March, in conjunction with Prof. Christie.--In January I applied to Lord Auckland for money-assistance to make an astronomical journey on the Continent, but he refused.--On Mar. 19th Sir James South addressed to the Admiralty a formal complaint against me for not observing with the astronomical instruments: on Mar. 31st I was triumphantly acquitted by the Admiralty.--In June I was requested by the Commissioners of Railways to act as President of a Commission on Iron Bridges (suggested by the fall of the bridge at Chester). Lord Auckland objected to it, and I was not sorry to be spared the trouble of it.--In December I was requested, and undertook to prepare the Astronomical part of the Scientific Manual for Naval Officers.--On Sept. 24th occurred a very remarkable Magnetic Storm, to which there had been nothing comparable before. Mr Glaisher had it observed by eye extremely well, and I printed and circulated a paper concerning it.--Hansen, stimulated by the Lunar Reductions, discovered two long inequalities in the motion of the Moon, produced by the action of Venus. In the Report to the Visitors this matter is thus referred to: 'In the last summer I had the pleasure of visiting Prof. Hansen at Gotha, and I was so fortunate as to exhibit to him the corrections of the elements from these Reductions, and strongly to call his attention to their certainty, the peculiarity of their fluctuations, and the necessity of seeking for some physical explanation. I have much pleasure in indulging in the thought, that it was mainly owing to this representation that Prof. Hansen undertook that quest, which has terminated in the discovery of his two new lunar inequalities, the most remarkable discovery, I think, in Physical Astronomy.'--In discussing points relating to the discovery of Neptune, I made an unfortunate blunder. In a paper hastily sent to the Athenaeum (Feb. 18th) I said that Arago's conduct had been indelicate. I perceived instantly that I had used a wrong expression, and by the very next post I sent an altered expression. This altered expression was not received in time, and the original expression was printed, to my great sorrow. I could not then apologize. But at what appeared to be the first opportunity, in December, I did apologize; and my apology was accepted. But I think that Arago was never again so cordial as before.--On July 4th Hebe was discovered. After this Iris and Flora. Now commenced that train of discoveries which has added more than 100 planets to the Solar System.--On Oct. 8th was an Annular Eclipse of the Sun, of which the limit of annularity passed