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The state of being colored, as in the case of images formed by a lens.

ies of pictures, moved rapidly (25 to 50 a second) and intermittently before an objective lens, and producing by persistence of vision the illusion of continuous motion; a moving-picture machine; also, any of several other machines or devices producing moving pictorial effects. Other common names for the cinematograph…

A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used.

nd convex sides as makes the focal axis the shortest line between them. See Illust. under Lens.

d water or air. See Illust. of Steam engine. Achromatic condenser (Optics), an achromatic lens used as a condenser. -- Bull's-eye condenser, or Bull's-eye (Optics), a lens of short focal distance used for concentrating rays of light. -- Injection condenser, a vessel in which steam is condensed by the direct contact o…

ncil of rays of light which proceed from a radiant point to a given surface, as that of a lens, or conversely. -- Cone pulley. See in the Vocabulary. -- Oblique or Scalene cone, a cone of which the axis is inclined to the plane of its base. -- Eight cone. See Cone, 1.

s of views in various parts of the world is seen reflected by mirrors through a series of lenses, with such illumination, etc., as will make the views most closely represent reality.

To treat by pushing down or displacing the opaque lens with a needle; as, to couch a cataract. To couch a spear or lance, to lower to the position of attack; to place in rest. He stooped his head, and couched his spear, And spurred his steed to full career. Sir W. Scott. To couch malt, to spread malt on a floor. Mortim…

The operation of putting down or displacing the opaque lens in cataract.

ithin it), in order to explain certain movements of the heavently bodies. -- Crystalline lens (Anat.), the capsular lenslike body in the eye, serving to focus the rays of light. It consists of rodlike cells derived from the external embryonic epithelium.

a section of its convex surface; partaking of the properties of the cylinder. Cylindrical lens, a lens having one, or more than one, cylindrical surface. -- Cylindric, or Cylindrical, surface (Geom.), a surface described by a straight line that moves according to any law, but so as to be constantly parallel to a given…

A falling away; decay; deterioration; declension. "The old castle, where the family lived in their decadence.' Sir W. Scott.

Capable of being declined; admitting of declension or inflection; as, declinable parts of speech.

The act of inflecting a word; declension. See Decline, v. t.,

Lacking some of the usual forms of declension or conjugation; as, a defective noun or verb. -- De*fect"ive*ly, adv. -- De*fect"ive*ness, n.

arvæ of which feed animal substances. They are very destructive to dries meats, skins, woolens, and furs. The most common species is D. lardarius, known as the bacon beetle.

The act of going downward; descent; falling or sinking; declension; degradation. Oblique descension (Astron.), the degree or arc of the equator which descends, with a celestial object, below the horizon of an oblique sphere. -- Right descension, the degree or arc of the equator which descends below the horizon of a ri…

omewhat like an apron. -- Devil's coachhorse. (Zoöl.) (a) The black rove beetle (Ocypus olens). [Eng.] (b) A large, predacious, hemipterous insect (Prionotus cristatus); the wheel bug. [U.S.] -- Devil's darning-needle. (Zoöl.) See under Darn, v. t. -- Devil's fingers, Devil's hand (Zoöl.), the common British starfish…

That which burns by refraction, as a double convex lens, or the sun's rays concentrated by such a lens, sometimes used as a cautery.

cope, an achromatic telescope in which the colored dispersion produced by a single object lens of crown glass is corrected by a smaller concave lens, or combination of lenses, of high dispersive power, placed at a distance in the narrower part of the converging cone of rays, usually near the middle of the tube.…