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granite
(Encyclopedia)granite, coarse-grained igneous rock of even texture and light color, composed chiefly of quartz and feldspars. It usually contains small quantities of mica or hornblende, and minor accessory minerals...watch
(Encyclopedia)watch, small, portable timepiece usually designed to be worn on the person. Other kinds of timepieces are generally referred to as clocks. At one time it was generally believed that the first watches ...gravel
(Encyclopedia)gravel, particles of rock, i.e., stones and pebbles, usually round in form and intermediate in size between sand grains and boulders. Gravel is composed of various kinds of rock, the most common const...piezoelectric effect
(Encyclopedia)piezoelectric effect pīēˌzōĭlĕkˈtrĭk [key], voltage produced between surfaces of a solid dielectric (nonconducting substance) when a mechanical stress is applied to it. A small current may be ...pitchblende
(Encyclopedia)pitchblende pĭchˈblĕndˌ [key], dark, lustrous, heavy mineral, a source of radium and uranium. Largely natural uranium oxides, triuranium octaoxide (U3O8) and uranium dioxide (UO2), it usually cont...searchlight
(Encyclopedia)searchlight, device, usually swiveled, using a lens and reflecting surface to direct a powerful beam of light of nearly parallel rays. In 1892 such apparatus was used along the English Channel in coas...oscillator, electronic
(Encyclopedia)oscillator, electronic ŏsˈəlāˌtər [key], electronic circuit that produces an output signal of a specific frequency. An oscillator generally consists of an amplifier having part of its output ret...clock
(Encyclopedia)CE5 A pendulum clock: Weight-driven clock mechanism clock, instrument for measuring and indicating time. Predecessors of the clock were the sundial, the hourglass, and the clepsydra. See also watc...hardness
(Encyclopedia)hardness, property of matter commonly described as the resistance of a substance to being scratched by another substance. The degree of hardness is relative, different substances being compared with o...Roraima
(Encyclopedia)Roraima ro͝orīˈmə [key], state (1996 pop. 247,724), 88,843 sq mi (230,103 sq km), NW Brazil, on the border of Venezuela and Guyana. Boa Vista is the capital. Located almost entirely in the Guiana ...Browse by Subject
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