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nuclear weapons

(Encyclopedia)nuclear weapons, weapons of mass destruction powered by atomic, rather than chemical, processes. Nuclear weapons produce large explosions and hazardous radioactive byproducts by means of either nuclea...

Wilkes, Charles

(Encyclopedia)Wilkes, Charles, 1798–1877, American naval officer and explorer, b. New York City, educated by his father. In 1815 he entered the merchant service and received (1818) an appointment as a midshipman....

boat

(Encyclopedia)boat, small, open nautical vessel propelled by sail, oar, pole, paddle, or motor. The use of the term boat for larger vessels, although common, is somewhat improper, but the line between boats and shi...

bearing

(Encyclopedia)bearing, machine part designed to reduce friction between moving parts or to support moving loads. There are two main kinds of bearings: the antifriction type, such as the roller bearing and the ball ...

Saint Lawrence Seaway

(Encyclopedia)Saint Lawrence Seaway, international waterway, 2,342 mi (3,769 km) long, consisting of a system of canals, dams, and locks in the St. Lawrence River and connecting channels between the Great Lakes; op...

air, law of the

(Encyclopedia)air, law of the, in the broadest sense, all law connected with the use of the air, including radio and satellite transmissions; more commonly, it refers to laws concerning civil aviation. The developm...

Bering Sea

(Encyclopedia)Bering Sea, c.878,000 sq mi (2,274,020 sq km), northward extension of the Pacific Ocean between Siberia and Alaska. It is screened from the Pacific proper by the Aleutian Islands. The Bering Strait co...

Theseus

(Encyclopedia)Theseus thēˈsyo͞os, –sēəs [key], in Greek mythology, hero of Athens; son of either King Aegeus or Poseidon. Before Aegeus left Troezen he placed his sword and sandals beneath a huge rock and to...

Antarctica

(Encyclopedia)CE5 Antarctica ăntärkˈtĭkə, –ärˈtĭkə [key], the fifth largest continent, c.5,500,000 sq mi (14,245,000 sq km), asymmetrically centered on the South Pole and almost entirely within the An...

Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...