PEIRCE, piers or plrs. BENJAMIN (1809.80), An Ameriea n mathematician and astronomer, born at Salem. Mass. Ile graduated at Harvard College in 1829. Ile became tutor there in 1831: professor of mathematics and physics in 1833, and Perkins professor of mathematics and as tronomy in 1842, which position he held till his death. In 1849 he hecalne consulting astronomer to the it))) criretn Ephemeris and Nautical Alma nac, and in 1853 one of the council to organize the Dudley Observatory, Albany. In 1807 he suc ceeded Professor A. D. Bache as superintendent of the Coast Survey, in which service he eontinned till 1874. In hi,. early life he was a contributor to the Mallo.matical Miscellany, and also published the Cambridge Miscellany of Mallwmaiies, Phys ics, and Astronomy, in which appeared his cele brated imostigation of the'inotion of a top spin ning on a plane surface. Ile also prepared a series of mathematical text books for the use of the university, and it was chiefly by his exertions that the llarvard Observatory was established and perfected. In 1851 he published in the Astronont ical Journal remarkable papers on the constitu tion of Saturn's rings, in which he considered the conditions of statical equilibrium of a transverse section of the ring, and came to the conclusion that if there are separate rings, they must be more numerous than Laplace had even supposed. (See
i'?ATERN.) In 1857 he imblished the System of Analytical Mechanics. Among his important con tributions to mechanics may be mentioned his in vestigation of the forms of an elastic sac con taining a fluid, a subject which led to the theory of analytic morphology. Ills contributions to mathematics are of the broadest and profoundest character. They are principally embraced in cer tain communications on Linear itssocialirc Alge bra, to the National Academy of Sciences, which had been suggested by the publication by Hamil ton in 1852 of his quaternions. These communica tions were collected in 1870, and 100 lithograph copies were published. It was reprinted in the meriean Journal of Mathematk's (1882). Peirce was a member of various learned societies in Europe and America.