TIANSTEEN, Coals-Ruin. a Norwegian astronomer, was b. at Christiania. Sept. 26, 1784. At first intended for the legat profession, he subsequently devoted himself entirely to the study of mathematical science. In "_814 he was appointed to the chair of mathematics in the university of Christiania, and there, in 1819, published his cele brated work on magnetism, which was afterwards translated into German under the title of Untersuelinugen Om. den der .Erde, and produced a great sensation, especially in England, so much so, that in almost all the voyages of discovery since undertaken, magnetic observations have been made in conformity to his directions. In 1821 he discovered the "law of magnetic force." See After having visited London, Paris, Hamburg, Berlin, and different parts of his native country, he resolved to undertake a journey to Siberia, for the purpose of continuing his magnetic observations, which he accomplished from 1828 to 1830, and returned to Europe with a large collection of facts, which were of much service in aiding to dispel the obscurity which enveloped and still partly envelops this subject. On his return to Christiania, he
prevailed upon the government to erect an observatory, fitted also for magnetic observa tions. Besides occupying his chair in the university, Hansteen was professor of mathe matics in the school of artillery, superintended the triangulation of Norway, and helped in the reorganization of the national system of weights and measures. He died April 15, 1873. He published lectures on astronomy, a work on mechanics, another on geometry, and several memoirs, of which the greater part are inserted in the _littgaila far Alaturcidenskaberne.