Columbia Encyclopedia

Search results

500 results found

photoelectric effect

(Encyclopedia)photoelectric effect, emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory ...

capacitor

(Encyclopedia)capacitor or condenser, device for the storage of electric charge. Simple capacitors consist of two plates made of an electrically conducting material (e.g., a metal) and separated by a nonconducting ...

saddle

(Encyclopedia)saddle, seat or pad to support the rider on an animal, chiefly a horse. The saddles mentioned in the Bible are generally considered to have been saddlecloths. The ancient Greeks sometimes used saddlec...

solar time

(Encyclopedia)solar time, time defined by the position of the sun. The solar day is the time it takes for the sun to return to the same meridian in the sky. Local solar time is measured by a sundial. When the cente...

Tlingit

(Encyclopedia)Tlingit tlĭngˈgĭt [key], group of related Native North American tribes, speaking a language that forms a branch of the Nadene linguistic stock (see Native American languages). The 14 divisions of t...

Peale, Charles Willson

(Encyclopedia)Peale, Charles Willson pēl [key], 1741–1827, American portrait painter, naturalist, and inventor, b. Queen Annes County, Md. Charles Willson Peale's brother James Peale, 1749–1831, b. Cheste...

differential geometry

(Encyclopedia)differential geometry, branch of geometry in which the concepts of the calculus are applied to curves, surfaces, and other geometric entities. The approach in classical differential geometry involves ...

Durban

(Encyclopedia)Durban dûrˈbən [key], city, now part and seat of eThekwini metropolitan municipality, KwaZulu-Natal prov., E South Africa, on Natal Bay, an arm of the Indian Ocean. Durban is an industrial center, ...

Harlan, John Marshall, 1833–1911, associate justice of the U.S. Supreme Court

(Encyclopedia)Harlan, John Marshall, 1833–1911, American jurist, associate justice of the U.S. Supreme Court (1877–1911), b. Boyle co., Ky., grad. Centre College, 1850. Admitted to the bar in 1853, he served in...

harmonica

(Encyclopedia)harmonica. 1 The simplest of the musical instruments employing free reeds, known also as the mouth organ or French harp. It was probably invented in 1829 by Friedrich Buschmann of Berlin, who called h...