Friday, November 18, 2005


The basic structure and composition of the Earth's interior have been known since the mid-20th century. In a landmark paper published in 1952, the American geophysicist Francis Birch described the constitution of the planetary interior based on a broad array of seismological, experimental, and geochemical observations. Although there have been numerous advances in

Sunday, October 16, 2005


Region of northern Guatemala, bounded on the north and west by Mexico and on the east by Belize. It constitutes more than one-third of the nation's territory. Petén is a low limestone plateau, varying in elevation between 500 and 700 feet (150 and 210 m) above sea level at the base of the Yucatán Peninsula. Except for areas of savanna vegetation, the region is covered by dense tropical rain

Monday, August 08, 2005


City, northeastern New South Wales, Australia. It lies on the valley slopes of Dumaresq Creek in the New England Range. Founded in 1839 by G.J. Macdonald, commissioner of crown lands, and named for his father's Scottish baronial estate on the Isle of Skye, it developed a pastoral-agricultural economy. It has become a regional cultural centre with Anglican and Roman Catholic

Wednesday, July 27, 2005

Bridges, Harry

Bridges left home to become a maritime seaman at the age of 16 and in 1920 legally entered the United States, where he worked as a seaman and dockworker

Saturday, July 23, 2005

F Region

Highest region of the ionosphere, at altitudes greater than 160 km (100 miles); it has the greatest concentration of free electrons and is the most important of the ionospheric regions. The charged particles in the F region consist primarily of neutral atoms split into electrons and charged atoms. Although its degree of ionization persists with little change through the

Friday, July 08, 2005

Karamzin, Nikolay Mikhaylovich

From an early age, Karamzin was interested in Enlightenment philosophy and western European literature. After extensive travel in western Europe,

Wednesday, July 06, 2005


City, capital of Botosani judet (county), northeastern Romania. It lies in a rich farming area of northern Moldavia, near the border with Moldova. As a settlement, it was first documented in 1439. The Popauti Church dates from 1496. Long known as a market centre for agricultural produce and wines, Botosani has also become an industrial centre, particularly in textiles. Pop. (1989 est.) 119,563.