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Elyria

(Encyclopedia)Elyria ēlērˈēə [key], city (2020 pop. 52,656), seat of Lorain co., N Ohio, on the Black ...

John Henry

(Encyclopedia)John Henry, legendary African American famous for his strength, celebrated in ballads and tales. In the most popular version of the story, John Henry tries to outwork a steam drill with only his hamme...

Stavropol

(Encyclopedia)Stavropol stäˈvrəpəl [key], city (1989 pop. 318,000), capital of Stavropol Territory, S European Russia, on the Stavropol Plateau. It has machine-tool, wool, leather, grain milling, and food-proce...

pillbox

(Encyclopedia)pillbox, small, low fortification that houses machine guns and antitank weapons. Similar to a blockhouse, it is usually made of concrete, steel, logs, or filled sandbags. Pillboxes came into use durin...

Carlson, Chester Floyd

(Encyclopedia)Carlson, Chester Floyd, 1906–68, American inventor; b. Seattle, Wash. A patent lawyer, he invented (1938) xerography, a method of electrostatic printing. For the next two decades he struggled to fin...

boring mill

(Encyclopedia)boring mill, machine tool used to increase the size of a hole previously made in a workpiece, usually with the purpose of obtaining a required degree of finish and accuracy in the final hole. In a hor...

reaper

(Encyclopedia)reaper, early farm machine drawn by draft animals or tractor and used to harvest grain. Its historical predecessors were the sickle and the cradle scythe, which are still used in some parts of the wor...

screw

(Encyclopedia)screw, simple machine consisting essentially of a solid cylinder, usually of metal, around which an inclined plane winds spirally, either clockwise or counterclockwise. It is used to fasten one object...

brake, in technology

(Encyclopedia)CE5 Shoe brake CE5 Disk brake brake, in technology, device to slow or stop the motion of a mechanism or vehicle. The vacuum brake system, or vacuum brake, depends upon the use of a vacuum to ...

small arms

(Encyclopedia)small arms, firearms designed primarily to be carried and fired by one person and, generally, held in the hands, as distinguished from heavy arms, or artillery. Automatic small arms were develope...