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microphone

(Encyclopedia)microphone, device for converting sound into electrical energy, used in radio broadcasting, recording, and sound amplifying systems. Its basic component is a diaphragm that responds to the pressure or...

vibration

(Encyclopedia)vibration, in physics, commonly an oscillatory motion—a movement first in one direction and then back again in the opposite direction. It is exhibited, for example, by a swinging pendulum, by the pr...

Croatoan

(Encyclopedia)Croatoan, unexplained letters found (1590) carved on a tree on Roanoke Island off North Carolina by Gov. John White when he returned to the colony from England and discovered the colonists gone. White...

Georgia, Strait of

(Encyclopedia)Georgia, Strait of, channel, c.150 mi (240 km) long, between the mainland of British Columbia and Vancouver Island, Canada, between Puget Sound and Queen Charlotte Sound. It forms part of the inland s...

Killigrew, Thomas

(Encyclopedia)Killigrew, Thomas kĭlˈəgro͞oˌ [key], 1612–83, English dramatist and theater manager, b. London. Before the closing of the theaters by the Puritans in 1642, he wrote several tragicomedies, inclu...

Caroline of Brunswick

(Encyclopedia)Caroline of Brunswick, 1768–1821, consort of George IV of England. The daughter of Charles William Ferdinand, duke of Brunswick, she married George (then prince of Wales) in 1795. She bore him one d...

Verdun, battle of

(Encyclopedia)Verdun, battle of, the longest and one of the bloodiest engagements of World War I. Two million men were engaged. It began on Feb. 21, 1916, when the Germans, commanded by Crown Prince Frederick Willi...

audio frequency

(Encyclopedia)audio frequency: see sound; radio. ...

record player

(Encyclopedia)record player or phonograph, device for reproducing sound that has been recorded as a spiral, undulating groove on a disk. This disk is known as a phonograph record, or simply a record (see sound reco...

Lee, Henry

(Encyclopedia)Lee, Henry, 1756–1818, American Revolutionary soldier, known as Light-Horse Harry Lee, b. Prince William co., Va. He was a cousin of Arthur Lee, Francis L. Lee, Richard H. Lee, and William Lee and w...