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Tagore, Sir Rabindranath

(Encyclopedia)Tagore, Sir Rabindranath rəbĭnˈdrənät təgôrˈ, täko͝orˈ [key], 1861–1941, Indian author and guru, b. Calcutta (now Kolkata). Tagore came from a wealthy Bengali family. He went abroad in 18...

soap

(Encyclopedia)soap, a cleansing agent. It cleanses by lowering the surface tension of water, by emulsifying grease, and by absorbing dirt into the foam. Ancient peoples are believed to have employed wood ashes and ...

Euclid, Greek mathematician

(Encyclopedia)Euclid yo͞oˈklĭd [key], fl. 300 b.c., Greek mathematician. Little is known of his life other than the fact that he taught at Alexandria, being associated with the school that grew up there in the l...

flame

(Encyclopedia)flame, phenomenon associated with the chemical reaction of a gas that has been heated above its kindling temperature with some other gas, usually atmospheric oxygen (see combustion). The heat and ligh...

frontier

(Encyclopedia)frontier, in U.S. history, the border area of settlement of Europeans and their descendants; it was vital in the conquest of the land between the Atlantic and the Pacific. The importance of the westwa...

blood clotting

(Encyclopedia)blood clotting, process by which the blood coagulates to form solid masses, or clots. In minor injuries, small oval bodies called platelets, or thrombocytes, tend to collect and form plugs in blood ve...

torpedo , in naval warfare

(Encyclopedia)torpedo, in naval warfare, a self-propelled submarine projectile loaded with explosives, used for the destruction of enemy ships. Although there were attempts at subsurface warfare in the 16th and 17t...

screen

(Encyclopedia)screen, in architecture, partition or enclosure not extending to the ceiling; usually a structure in stone, wood, or metal. It frequently serves to mark the boundaries of portions of churches and cath...

Courbet, Gustave

(Encyclopedia)Courbet, Gustave güstävˈ ko͞orbāˈ [key], 1819–77, French painter, b. Ornans. He moved to Paris in 1839 and studied there, learning chiefly by copying masterpieces in the Louvre. An avowed real...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...