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Rockefeller Center

(Encyclopedia)Rockefeller Center, complex of buildings in central Manhattan, New York City, between 48th and 51st streets and Fifth Ave. and the Ave. of the Americas (Sixth Ave.). The project was sponsored by John ...

Baltimore & Ohio Railroad

(Encyclopedia)Baltimore & Ohio Railroad (B&O), first U.S. public railroad, chartered in 1827 by a group of Baltimore businessmen to regain trans-Allegheny traffic lost to the newly opened Erie Canal. Constr...

lock and key

(Encyclopedia)lock and key, fastening fitted to an entryway, such as a gate or door, or a container, such as a cabinet, drawer or safe, to keep it closed and/or prevent unauthorized access or use. Locks typically c...

Hancock, Herbie

(Encyclopedia) Hancock, Herbie (Herbert Jeffrey Hancock), 1940- , American jazz pianist, composer, and bandleader, b. Chicago, Il., Grinnell College (B.S.E., 1960, H...

lock, canal

(Encyclopedia)lock, canal, stretch of water enclosed by gates, one at each end, built into a canal or river for the purpose of raising or lowering a vessel from one water level to another. A lock may also be built ...

magnetron

(Encyclopedia)magnetron măgˈnĭtrŏnˌ [key], vacuum tube oscillator (see electron tube) that generates high-power electromagnetic signals in the microwave frequency range. Its operation is based on the combined ...

torque

(Encyclopedia)torque, in physics, that which tends to change the rate of rotation of a body; also called the moment of force. The torque produced by rotating parts of an electric motor or internal-combustion engine...

Bjerknes, Vilhelm Frimann Koren

(Encyclopedia)Bjerknes, Vilhelm Frimann Koren vĭlˈhĕlm frēˈmän kôˈrən byĕrkˈnĕs [key], 1862–1951, Norwegian physicist and pioneer in modern meteorology. He worked on applying hydrodynamic and thermody...

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...

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...