Columbia Encyclopedia

Search results

500 results found

nail, in anatomy

(Encyclopedia)nail, in anatomy, the horny outgrowth shielding the tip of the finger and the toe in humans and most other primates. The nail consists of dead cells pushed outward by dividing cells in the root, a fol...

aerogel

(Encyclopedia)aerogel, any of a group of extremely light and porous solid materials; the lightest is less than four times as dense as dry air. Aerogels are produced from certain gels (see colloid) by heating the ge...

aerosol dispenser

(Encyclopedia)aerosol dispenser, device designed to produce a fine spray of liquid or solid particles that can be suspended in a gas such as the atmosphere. The dispenser commonly consists of a container that holds...

casting

(Encyclopedia)casting or founding, shaping of metal by melting and pouring into a mold. Most castings, especially large ones, are made in sand molds. Sand, mixed with a binder to hold it together, is pressed around...

catapult

(Encyclopedia)catapult kătˈəpŭltˌ [key], mechanism used to throw missiles in ancient and medieval warfare. At first, catapults were specifically designed to shoot spears or other missiles at a low trajectory (...

Canyonlands National Park

(Encyclopedia)Canyonlands National Park, 337,598 acres (136,679 hectares), SE Utah; est. 1964. Located in a desert region, the park contains a maze of deep canyons and many unusual features carved by wind and water...

Windischgrätz, Alfred, Fürst zu

(Encyclopedia)Windischgrätz or Windisch-Grätz, Alfred, Fürst zu älˈfrāt fürst tso͞o vĭnˈdĭshgrĕtsˈ [key], 1787–1862, Austrian field marshal. He was military governor of Bohemia when the revolutions o...

varicose vein

(Encyclopedia)varicose vein, superficial vessel that is abnormally lengthened, twisted, or dilated, seen most often on the legs and thighs. Varicose veins develop spontaneously, and are usually attributed to a here...

vegetarianism

(Encyclopedia)vegetarianism, theory and practice of eating only fruits and vegetables, thus excluding animal flesh, fish, or fowl and often butter, eggs, and milk. In a strict vegetarian, or vegan, diet (i.e., one ...

speedometer

(Encyclopedia)speedometer, instrument that indicates speed. A cable from an automotive speedometer is attached to the rear of the transmission of an automobile; the cable turns at a rate proportional to the speed o...