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Douglas, Donald Wills

(Encyclopedia)Douglas, Donald Wills, 1892–1981, aviation pioneer and aerospace executive, b. Brooklyn, N.Y., B.S. Massachusetts Institute of Technology, 1914. He helped design the first wind tunnel (1914–15) an...

water wheel, device

(Encyclopedia)water wheel, device for utilizing the power of flowing or falling water. The Norse wheel is the oldest type known. Despite its name it probably originated in the Middle East, where the swift stream re...

plow

(Encyclopedia)plow or plough, agricultural implement used to cut furrows in and turn up the soil, preparing it for planting. The plow is generally considered the most important tillage tool. Its beginnings in the B...

Langley, Samuel Pierpont

(Encyclopedia)Langley, Samuel Pierpont, 1834–1906, American scientist, b. Roxbury, Mass., received only a high school education but continued his studies in science in Boston libraries. He became, in 1866, profes...

compression

(Encyclopedia)compression, external stress applied to an object or substance, tending to cause a decrease in volume (see pressure). Gases can be compressed easily, solids and liquids to a very small degree if at al...

pump

(Encyclopedia)pump, device to lift, transfer, or increase the pressure of a fluid (gas or liquid) or to create a vacuum in an enclosed space by the removal of a gas (see vacuum pumps under vacuum). The centrifugal ...

vertical takeoff and landing aircraft

(Encyclopedia)vertical takeoff and landing aircraft (VTOL), craft capable of rising and descending vertically from and to the ground, thus requiring no runway. While a balloon or an airship has obvious VTOL capabil...

shock absorber

(Encyclopedia)shock absorber, device for reducing the effect of a sudden shock by the dissipation of the shock's energy. On an automobile, springs and shock absorbers are mounted between the wheels and the frame. W...

Radek, Karl

(Encyclopedia)Radek, Karl kärl räˈdyĭk [key], 1885–1939?, international Communist leader and journalist, b. Lviv (then in Austrian Poland); his original name was Sobelsohn. Radek participated in the 1905 revo...

steering system

(Encyclopedia)steering system, in automobiles, steering wheel, gears, linkages, and other components used to control the direction of a vehicle's motion. Because of friction between the front tires and the road, es...