Arch i me des

(ar-ke-me'dēēz,) the most celebrated mathematician among the ancients, was a native of Syracuse, and related to King Hieron. He was equally skilled in the sciences of astronomy, geometry, mechanics, hydrostatics, and optics. The combination of pulleys for raising heavy weights, the Arch i me dean screw, a sphere to represent the motions of the heavenly bodies, ., were invented by him; but his genius for invention was never more signally displayed than in the defence of his native city, when besieged by Mar cell us; although the well-known story that among other astonishing novelties he produced a burning-gla composed of reflecting mirrors, by which he fired the enemy's fleet, is most likely a fiction of later times, no mention of such a circumstance occurring earlier than the 12th cent. At length, however, the city was taken by storm, and A., then in his 74th year, was among the slain, B. c. 212. [s. 43]