Johann Heiurich Lambert, a German philosopher, born in Muhlhausen, Alsace, Aug. 29, 1728, died in Berlin, Sept. 25, 1777. He was the son of a poor tailor, and was chiefly self-educated. He was at first a copying clerk, afterward secretary to the editor of a news-paper at Basel. In 1748 he went to Coire in Switzerland, and became private tutor in the family of Count Peter de Salis, then president of the confederation. In 1756-'8 he visited Holland, France, and Italy with his pupils. In 1759 he removed to Augsburg, but, having been appointed to determine the boundaries between the country of the Grisons and the Milanese, he returned to Coire in 1761, and sojourned there till 1763. In 1764 he went to Berlin, and was made a member of the royal academy of sciences; in 1770 he was appointed superior councillor of the board of works; and in 1774 was intrusted with the superintendence of the "Astronomical Almanac." He was regarded as the most analytical writer on scientific subjects of his day. The measurement of the intensity of light was first reduced to a science in his Pliotometria (Augsburg, 1760), and the theory of refraction was developed in Les proprieties remarquables de la route de la lumiere par les airs (the Hague, 1759; Ger. translation, Berlin, 1773). Among his other works are: Die freie Perspective (Zurich, 1759); Kosmologische Briefe uber die Einrich-tung des Weltbaues (Augsburg, 1761); Insig-niores Orbitce Cometarum Proprietates (1761); Neues Organon (Leipsic, 1764); Beitrage zum Gebrauch der Mathematik (Berlin, 1765-72); and Anlage zur Architektonik (Riga, 1771). His correspondence with Kant appears in the minor miscellaneous works of the latter.