« PreviousContinue »
A NEW AND CERTAIN METHOD
THE FIGURE OF THE EARTH
BY MEANS OF
OCCULTATIONS OF THE FIXED STARS.
By A. CAGNOLI.
NOTES AND AN APPENDIX
BY FRANCIS BAILY.
THE following Memoir originally appeared in the Transactions of the Italian Society (Memorie di Matematica e di Fisica della Società Italiana. Tom. vi. Verona 1792): but, although it has been so many years before the public, I do not find that the subject of it has been taken up by any persons either here, or on the continent. In fact, I believe that it is not generally known in this country and it is with a view of drawing the attention of astronomers more closely to it, that I now present them with this translation. The acknowledged talents and abilities of the Author must at all times ensure it an attentive perusal : but particularly at this period, when a more than ordinary degree of interest is excited towards the subject of the true figure of the Earth. I am aware that there are some apparent difficulties in the method pointed out in the Memoir, yet
not without hope and expectation that they may be eventually overcome: and that the mode herein proposed may at least be brought in aid of the other methods at present adopted for determining that difficult problem.
To the Memoir itself I have subjoined some Notes connected with the subject; which, however, may be distinguished from those of the Author by the addition of the letter B. And to the whole I have added an Appendix, wherein I have attempted to illustrate the views of the Author; and ventured to propose such methods as may best tend to carry his object into execution.
GRAY'S INN, May 20, 1819,
As the present Memoir is not published for sale, I shall be happy to furnish such persons, as may send their Cards for that purpose, with any number of copies they may require.
A new and certain Method of ascertaining the Figure of the Earth.
By A. CAGNOLI.
1. THE truth of the Newtonian theory of universal gravitation is proved by the wonderful agreement in all the celestial phænomena, which have hitherto been submitted to the tests of calculation and of observation. There probably is not any astronomer of the present day who is not convinced that our planet is compressed, or flattened, at the poles, and protuberant at the equator. In fact, if we combine this theory of Newton with the hypothesis of the elliptical form of the earth, we shall find that the precession of the equinoxes and the nutation of the earth's axis are sufficiently accounted for. Other arguments indeed, in favour of the elliptical form, may be derived from the rotation of the earth, which is now generally admitted: