Columbia Encyclopedia

Search results

500 results found

fatigue, in physiology

(Encyclopedia)fatigue, in physiology, inability to perform reasonable and necessary physical or mental activity. Muscle fatigue, for example, results when the contractile properties of muscle are reduced, and conti...

elevator, in machinery

(Encyclopedia)elevator, in machinery, device for transporting people or goods from one level to another. The term is applied to the enclosed structures as well as the open platforms used to provide vertical transpo...

emanation, in philosophy

(Encyclopedia)emanation ĕmənāˈshən [key] [Lat.,=flowing from], cosmological concept that explains the creation of the world by a series of radiations, or emanations, originating in the godhead. It is character...

bark, in botany

(Encyclopedia)bark, outer covering of the stem of woody plants, composed of waterproof cork cells protecting a layer of food-conducting tissue—the phloem or inner bark (also called bast). As the woody stem increa...

scale, in cartography

(Encyclopedia)scale, in cartography, the ratio of the distance between two points on a map to the real distance between the two corresponding points portrayed. The scale may be expressed in three ways: numerically,...

scale, in music

(Encyclopedia)scale, in music, any series of tones arranged in a step-by-step rising or falling order of pitch. A scale defines the interval relationship of each tone to the others upon which the composition depend...

scale, in zoology

(Encyclopedia)scale, in zoology, an outgrowth, either bony or horny, of the skin of an animal. The major component of the scales of fishes is bone, and they are formed directly in the skin membrane as the fish grow...

rocket, in botany

(Encyclopedia)rocket, in botany, popular name for several plants of the family Cruciferae (or Brassicaceae; mustard family). The dame's, or damask, violet, damewort, or sweet rocket is Hesperis matronalis, a hardy,...

Browse by Subject