Torus

torus

[′tȯr·əs]

(anatomy)

A rounded protuberance occurring on a body part.

(botany)

The thickened membrane closing a bordered pit.

(mathematics)

The surface of a doughnut-shaped object.

The topological space obtained by identifying the opposite sides of a rectangle.

The group which is the product of two circles.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

torus

torus molding

torus

A bold projecting molding, convex in shape, generally forming the lowest member of a base over the plinth.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Torus

 

a geometric solid formed by the rotation of a circle about a line lying in the plane of the circle but not intersecting the circle (see Figure 1). A torus is shaped approximately like a doughnut or a life ring. If the radius of the rotating circle is r and

Figure 1

the distance from the center of the circle to the axis of rotation is a, then the area of the surface of the torus is 4π²ar and the volume of the torus is 2π²ar². The term “torus” is also applied to the surface bounding such a solid.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.