LOBACHEVSKY, or LOBATCHEW SKY, Nicholas Ivanovitch, Russian mathema tician: b. Makareif, Nyni-Novgorod, 1793; d. 24 Feb. 1856. He entered the University of Kazan in 1807, became assistant professor of mathematics in 1814 and extraordinary pro fessor in 1816. In 1823 he became ordinary professor retaining his chair (in addition being for 19 years rector) until 1846, when he fell into disfavor. Unlike many professional men, he was a good business man and his adminis tration of the affairs of the university was marked by many beneficial changes. He or ganized the force of teachers, and even studied architecture, so that when the new buildings were erected he supervised their erection, econ omized space and saved thousands of dollars. He wrote his (Pangeometrie) in 1855, giving the result of his long years of geometrical studies, and presented it to the university. He was one of the first thinkers to apply a critical treatment to the Euclidean principles of geom etry. He gave his first contribution to the
theory of hyper-geometry in a lecture at Kazan in 1826, hut later wrote several treatises on the subject. He also wrote a treatise on algebra (Kazan 1834) and contributed many other arti cles on mathematics. His complete works were edited by Janischevsky (1870) and have been translated by several writers. His collec tion of geometrical writings was published in Kazan in 1883, the first volume containing Rus sian articles only, and the second and last vol ume containing the French and German arti cles. For his geometry consult New Princi ples of Geometry with Complete Theory of Parallels,' translated by Halsted (Austin, Tex. 1897). Consult also Engel, F., 'N. I. Lobatchewsky' (Leipzig 1899).