Page:Proceedings of the Royal Society of London Vol 4.djvu/293

Rh into provinces of knowledge which were somewhat foreign to his own, that he was accustomed to quote the adage of Seneca : " Soleo €t in alie7ia castra transire, non tanquam transfuga^ sed tanquam explorator."

Blumenbach had long been considered as the patriarch of the University of Gottingen, and was allowed the full privileges attached to his distinguished reputation, to the memory of his long services, and to the respect due to his venerable old age ; he retained his usual cheerfulness, his memory, and much of his ancient activity, until nearly the close of his life. He died on the 22nd of January last, in the 88th year of his age, a memorable proof that the tran- quil pursuits of science and the gentle stimulus of constant though not laborious employments are equally favourable to contentment of mind and length of days.

The name of the venerable Dr. Olbers, of Bremen, must be for ever memorable in the annals of astronomy, as the discoverer of two planets inoursystem. He was a member of that remarkable association of twenty-four astronomers which the indefatigable Baron de Zach of Gotha had formed towards the close of the last century, who under- took the vigilant observation of as many zones of the heavens, with a general view of discovering new comets and planets, and of recording any remarkable phenomena that might occur. Their zeal in the prosecution of these researches had been stimulated by the recent discovery of Herschel, as well as by the revival of a suggestion made by Kepler of the probable existence of a planet between Mars and Jupiter, in conformity with one of those mystical ana- logies, which might have been treated as the visionary dreams of an enthusiast, if they had not been so intimately connected with the discovery of the great laws forming the true basis of all cor- rect knowledge of the system of the universe. The absence like- wise of a planet at the distance from the sun, represented by 28, that of the earth being 10, interfered with the completeness of an em- pirical law which Bode of Berlin had suggested, and was not with- out its influence in confirming their faith in these extraordinary an- ticipations. The labours of this Association had been hardly organ- ized, when the remarkable discovery of Ceres by Piazzi on the first day of the present century, in almost the precise position which Bode's singular law had assigned to it, seemed at once to convert their dreams into realities. Dr. Olbers calculated a circular, and Gauss an elliptic orbit for the same planet ; and so wonderful was the accuracy of the first approximation to the elements which the latter had made, that they enabled Olbers to re-discover it on the 1st of January 1802; exactly one year after it had been first ob- served. It was in consequence of having formed a configuration of stars in the geocentric route of this planet, with a view to its being more readily found, that he discovered Pallas on the 2.5th of March of the same year*, at nearly the same distance from the sunf,


 * " Ueber einen neuen von Dr. Gibers in Bremen endeckten hbchst sonderbaren cometen." Zach's Monatliche Correspondenz for May, 1802.

t If the distance of the earth from the sun be 1, that of Ceres is 2 '7674,