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Braille, Louis

(Encyclopedia)Braille, Louis brāl, Fr. lwē brīˈyə [key], 1809?–1852, French inventor of the Braille system of printing and writing for the blind. Having become blind from an accident at the age of 3, he was ...

astronomical coordinate systems

(Encyclopedia)astronomical coordinate systems. A coordinate system is a method of indicating positions. Each coordinate is a quantity measured from some starting point along some line or curve, called a coordinate ...

Atlas Mountains

(Encyclopedia)Atlas Mountains, system of ranges and plateaus in NW Africa, extending c.1,500 mi (2,410 km) from SW Morocco, through N Algeria, to N Tunisia; Jebel Toubkal (13,671 ft/4,167 m), in SW Morocco, is the ...

leukemia

(Encyclopedia)leukemia lo͞okēˈmēə [key], cancerous disorder of the blood-forming tissues (bone marrow, lymphatics, liver, spleen) characterized by excessive production of immature or mature leukocytes (white b...

Lancaster, Joseph

(Encyclopedia)Lancaster, Joseph, 1778–1838, English educator. In 1801 he founded a free elementary school, using a type of monitorial system for which he acknowledged his debt to Andrew Bell. The Royal Lancasteri...

heart-lung machine

(Encyclopedia)heart-lung machine, device that maintains the circulation of the blood and the oxygen content of the body when connected with the arteriovenous system; it is also called the pump oxygenator. The machi...

corvée

(Encyclopedia)corvée kôrvāˈ [key], under the feudal system, compulsory, unpaid labor demanded by a lord or king and the system of such labor in general. There were national and local variations, but in broad te...

control systems

(Encyclopedia)control systems, combinations of components (electrical, mechanical, thermal, or hydraulic) that act together to maintain actual system performance close to a desired set of performance specifications...

exoplanet

(Encyclopedia)exoplanet or extrasolar planet, a planet located outside the solar system. See planet; planetary system. ...

standpipe

(Encyclopedia)standpipe, tank or pipe for holding water in an elevated position to create pressure in a water supply system. For a tall building, where the pressure from the mains at street level is insufficient to...