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arc, in electricity

(Encyclopedia)arc, in electricity, highly luminous and intensely hot discharge of electricity between two electrodes. The arc was discovered early in the 19th cent. by the English scientist Sir Humphry Davy, who so...

McComb, John

(Encyclopedia)McComb, John, 1763–1853, American architect, b. New York City. He was chiefly known for the New York City Hall (1803–12), one of the finest American buildings of the postcolonial period, designed ...

Wagram

(Encyclopedia)Wagram doich– [key], town, Lower Austria prov., NE Austria, in the Marchfeld, near Vienna. On July 5–6, 1809, Napoleon I gained one of his most brilliant victories there. Despite their heroic cond...

rheostat

(Encyclopedia)rheostat rēˈəstătˌ [key], device whose resistance to electric current depends on the position of some mechanical element or control in the device. Typically a rheostat consists of a resistance el...

furnace

(Encyclopedia)furnace, enclosed space for the burning of fuel. There are many kinds of furnaces, the type depending upon the fuel and the use to which the heat produced within it is put. Most familiar are the furna...

palmtop

(Encyclopedia)palmtop or hand-held personal computer, lightweight, small, battery-powered, general-purpose programmable computer. It typically had a miniaturized full-function, typewriterlike keyboard for input and...

Whittingham, Michael Stanley

(Encyclopedia)Whittingham, Michael Stanley, 1941–, British-American chemist, Ph.D. Oxford, 1968. Whittingham worked for Exxon Research & Engineering from 1972 to 1984, then joined Schlumberger Ltd. In 1988, h...

energy

(Encyclopedia)CE5 Relations between potential energy (PE) and kinetic energy (KE) for a swinging pendulum energy, in physics, the ability or capacity to do work or to produce change. Forms of energy include hea...

electrostatics

(Encyclopedia)electrostatics, study of phenomena associated with charged bodies at rest (see charge; electricity). A charged body has an excess of positive or negative charges, a condition usually brought about by ...

ophthalmoscope

(Encyclopedia)ophthalmoscope ŏfthălˈməskōpˌ [key], instrument used for examining the inner structure of the eye. The device was invented by the German physiologist H. L. F. von Helmholtz in 1851. His model co...