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vernier

(Encyclopedia)vernier vûrˈnēr [key], auxiliary scale, either straight or an arc of a circle, designed to slide along a fixed scale. Its unit divisions, usually smaller than those on the fixed scale, permit a far...

coulomb

(Encyclopedia)coulomb ko͞oˈlŏm [key] [for C. A. de Coulomb], abbr. coul or C, unit of electric charge. The absolute coulomb, the current U.S. legal standard, is the amount of charge transferred in 1 second by a ...

Olympiad

(Encyclopedia)Olympiad, unit of a chronological era of ancient Greece, a four-year period, each one beginning with the Olympic games. Timaeus (c.356–c.260 b.c.) of Sicily was the first to use, as a check on chron...

Oroville Dam

(Encyclopedia)Oroville Dam, 770 ft (235 m) high and 7,600 ft (2,317 m) long, on the Feather River, N Calif., near the city of Oroville. The highest dam in the United States and the largest unit of the Feather River...

Sporades

(Encyclopedia)Sporades spôrˈədēz, spŏrˈ– [key], islands, E and SE Greece, in the Aegean Sea. They have been grouped variously at different times. The Northern Sporades are generally understood to include Sk...

Yakima, river, United States

(Encyclopedia)Yakima yăkˈəmô, –mə [key], river, 203 mi (327 km) long, rising in the Cascade Range, central Wash., and flowing SE past Yakima to the Columbia River near Kennewick. The U.S. Bureau of Reclamati...

turbine

(Encyclopedia)CE5 Types of turbines turbine, rotary engine that uses a continuous stream of fluid (gas or liquid) to turn a shaft that can drive machinery. A water, or hydraulic, turbine is used to drive electr...

astronomy

(Encyclopedia)astronomy, branch of science that studies the motions and natures of celestial bodies, such as planets, stars, and galaxies; more generally, the study of matter and energy in the universe at large. ...

light-year

(Encyclopedia)light-year, in astronomy, unit of length equal to the distance light travels in one sidereal year. It is 9.461 × 1012 km (about 6 million million mi). Alpha Centauri and Proxima Centauri, the stars n...

mole, in chemistry

(Encyclopedia)mole, in chemistry, a quantity of particles of any type equal to Avogadro's number, or 6.02×1023 particles. One gram-molecular weight of any molecular substance contains exactly one mole of molecules...