Columbia Encyclopedia

(Encyclopedia) Haavelmo, Trygve trügˈvə hävelmō [key], 1911–99, Norwegian economist. In the 1940s, he was a pioneer in the field of econometrics, using mathematics and statistics in the formation of economic ...

(Encyclopedia) New Red Sandstone, name for the thick red layer of the Triassic formation in Great Britain (see Triassic period). It is many thousands of feet thick and is composed chiefly of red sandstones, clays, a...

(Encyclopedia) geology, science of the earth's history, composition, and structure, and the associated processes. It draws upon chemistry, biology, physics, astronomy, and mathematics (notably statistics) for suppor...

(Encyclopedia) Hofmeister, Wilhelm vĭlˈhĕlm hōfˈmīˌstər [key], 1824–77, German botanist. Although self-taught, he made such valuable studies of the reproduction and development of plants that he was appoin...

(Encyclopedia) lobefin, common name for any of a group of lunged, fleshy-finned, bony fishes, also called crossopterygians, that were dominant in the Devonian period and may have given rise to amphibians. They had h...

(Encyclopedia) ginkgo gĭngˈkō [key] or maidenhair tree, tall, slender, picturesque deciduous tree (Ginkgo biloba) with fan-shaped leaves. The ginkgo is native to E China, where it was revered by Buddhist monks an...

(Encyclopedia) antacid, any one of several basic substances that counteract stomach acidity (see stomach). Antacids are used by physicians to treat hyperchlorhydria, i.e., the excessive production of hydrochloric ac...

(Encyclopedia) Sedgwick, Adam, 1785–1873, English geologist. He was a professor at Cambridge from 1818. His most important work was a study, made with R. I. Murchison, of the rock formation of Devonshire, which th...

(Encyclopedia) shale, sedimentary rock formed by the consolidation of mud or clay, having the property of splitting into thin layers parallel to its bedding planes. Shale tends to be fissile, i.e., it tends to split...

(Encyclopedia) Gobi gōˈbē [key], Mandarin Yintai shamo, great stony desert of N central Asia, c.500,000 sq mi (1,295,000 sq km), extending c.1,000 mi (1,610 km) from east to west across SE Mongolia and N China fr...