LAMBERT, JOITANN lImimex (1728-1777), physicist and mathematician, was born at Mulhausen, Alsace, August 29, 1728. He was the son of a tailor ; and the later recommended him as private tutor to the family of tunities for improving himself in his literary and scientific Utrecht, Paris, Marseilles, and Turin, he resigned his vals his home. Finally in 1761 he removed to Berlin, and ultimately (1774) undertook the editing of the to practical questions.

Lambert's most important work, Pyrometrie (Berlin, 1779), is a systematic treatise on heat, containing the records and full dimssion of many of his own experiments. Worthy of special notice also are Photometria, Augsburg, 1760 ; Insigniores orbitx Cometarum proprietates, Augsburg, 1761 ; and Beitrage zum Gebranche der Mathematilc and deren Anzvendung, 4 vols., Berlin, 1765-72.

The Memoirs of the Berlin Academy from 1761 to 1784 contain many of his papers, which treat of such subjects as resistance of fluids, magnetism, comets, probabilities, the problem of three bodies, meteorology, &c. In the Acta Helvetica (1752-60) and in the Xova Acta Erudita (1763-69) several of his contributions appear. In Bode's Jahrbuch (1776-80) he discusses natation, aberration of light, Saturn's rings, and comets ; in the Kova Acta Helvetica (1787) he has a long paper "Sur le Son des Corps Elastignes " ; in Bernoulli and Hindenburg's Magazin (1787-88) he treats of the roots of equations and of parallel lines ; and in Hindenburg's Archives (1798-99) he writes on optics and perspective. Many of these pieces were found among his effects after his death, and published posthumously. Recognized as among the first mathematicians of his day, he was also widely known for the universa:ity and depth of his philological and philosophical knowledge. The most valuable of his logical and philosophical memoirs were published collectively in 2 vols., 1782. See huber's Lambert mach seinen' Leben 'and Wirleen.