Rocks, like most materials, expand when they are heated. Some mountain ranges and plateaus are high simply because the crust and upper mantle beneath them are unusually hot. Most broad variations in the topography of the ocean floor, the mid-ocean ridges and rises, are due to horizontal variations in temperature in the outer 100 kilometres of the Earth. Hot areas stand
World War I, The Western Front, June–December 1917
Pétain's decision to remain temporarily on the defensive after Nivelle's failure gave Haig the opportunity to fulfill his desire for a British offensive in Flanders. He took the first step on June 7, 1917, with a long-prepared attack on the Messines Ridge, north of Armentières, on the southern flank of his Ypres salient. This attack by General Sir Herbert Plumer's 2nd Army proved
Uccello, Paolo
Original name Paolo Di Dono Florentine painter whose work attempted uniquely to reconcile two distinct artistic styles—the essentially decorative late Gothic and the new heroic style of the early Renaissance. Probably his most famous paintings are three panels representing “The Battle of San Romano” (c. 1456). His careful and sophisticated perspective
Banner System
Chinese (Wade–Giles romanization) Ch'i-ping, Pinyin Qibing, the military organization used by the Manchu tribes of Manchuria (now Northeast China) to conquer and control China in the 17th century. The Banner system was developed by the Manchu leader Nurhachi (1559–1626), who in 1601 organized his warriors into four companies of 300 men each. The companies were distinguished by banners of different colours—yellow, red, white, and blue. In 1615 four more
Mierkat
Also spelled Meerkat, common name for certain carnivores of the civet family (Viverridae): the suricate (q.v.) and various mongoose (q.v.) species.
Río Gallegos
Founded in 1885, it was named for Blasco Gallegos, one of Ferdinand Magellan's pilots, who is credited with discovering the river. Prehistoric cave paintings
Mamou
Town, west-central Guinea. Located on the Conakry-Kankan railway and at the intersection of roads from Kindia, Dalaba, Dabola, and Faranah, Mamou was founded in 1908 as a collecting point on the railroad from Conakry (125 miles [201 km] southwest). It is the chief trading centre for the rice, cattle, citrus fruits, bananas, tomatoes, and mangoes raised in the surrounding agricultural area.
