Autobiography of Sir George Biddell Airy eBook

George Biddell Airy
This eBook from the Gutenberg Project consists of approximately 516 pages of information about Autobiography of Sir George Biddell Airy.

Autobiography of Sir George Biddell Airy eBook

George Biddell Airy
This eBook from the Gutenberg Project consists of approximately 516 pages of information about Autobiography of Sir George Biddell Airy.
dates of their first and last appearances entered up to the present time.  Areas of spots have been measured, and the measures have been reduced to millionths of the Sun’s visible hemisphere.—­The examination of the readings of the deep-sunk thermometers from 1846 to 1873 has exhibited some laws which had been sufficiently established before this time, and some which were less known.  Among the former were the successive retardations of seasons in successive descents, amounting to about four months at the depth of 25 feet; and the successive diminutions of the annual range of temperature.  Among the latter is the character of the changes from year to year, which the great length of this series of observations brings well to light.  It is found that from year to year the mean temperature of the surface for the year, varying by three or four degrees of Fahrenheit, follows in its changes the mean temperature of the atmosphere for the year, and that the changes of annual temperature are propagated downwards, retarded in phase and diminishing in amount of change, in the same manner (though probably not following the same law) as the season changes.  The inference from this is, that changes of temperature come entirely from the exterior and in no discoverable degree from the interior; an inference which may be important in regard both to solar action and to geology.  —­Referring to the Transit of Venus observations:  In the astronomical part of the reductions, there has been great labour and difficulty in the determination of local sidereal times; some books of observations required extensive transcription; some instrumental errors are still uncertain; the latter determinations have perplexed us so much that we are inclined to believe that, in spite of the great facilities of reduction given by the transit instrument, it would be better to rely on the altazimuth for time-determinations....  In the photographic part, I have confined my attention entirely to measures of the distance between the centres of the Sun and Planet, a troublesome and complex operation.—­Referring to the progress of the Numerical Lunar Theory:  With a repetition of grant from the Treasury, I have usually maintained four junior computers on this work.  The progress, though considerable, has not been so great as I had hoped, by reason of the excessive personal pressure upon me during the whole year.—­I wrote a letter of congratulation to Le Verrier on the completion of his great work of Planetary Tables.—­On May 13th the Queen was at South Kensington, and I attended to explain the astronomical instruments, and shewed Her Majesty one of the Transit of Venus photographs.”

Of private history:  He returned from his Playford visit on the 18th of January.—­In April there was a two-day trip to Colchester.—­From June 13th to July 12th he was travelling in the North of Scotland and the Orkneys with his daughters, staying for a short time with Mr Webster, M.P., at Aberdeen, and with Mr Newall at Newcastle.—­In September there was a week’s run to Birkenhead and Keswick.—­In November a week’s run to Playford.—­From the 13th to 15th of December he was at Cambridge, and on the 28th he went to Playford for the usual winter stay there.

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Autobiography of Sir George Biddell Airy from Project Gutenberg. Public domain.