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The act of compressing, or state of being compressed. "Compression of thought." Johnson.

n small arms the modern projectile, having a soft core and harder jacket, is subjected to compression throughout the entire cylindrical part.

xis (Mech.), the line of demarcation between the horizontal elastic forces of tension and compression, exerted by the fibers in any cross section of a girder. -- Optic axis of a crystal, the direction in which a ray of transmitted light suffers no double refraction. All crystals, not of the isometric system, are eithe…

A premature explosion in the cylinder of a gas or oil engine during the exhaust or the compression stroke, tending to drive the piston in a direction reverse to that in which it should travel; also, an explosion in the exhaust passages of such ah engine.

the setting sun. Cunningham. Burnishing machine, a machine for smoothing and polishing by compression, as in making paper collars.

expansion to a desired point; (2) adiabatic expansion to a desired point; (3) isothermal compression to such a point that (4) adiabatic compression brings it back to its initial state.

in connection with a jar of water having an elastic top, to illustrate the effect of the compression or expansion of air in changing the specific gravity of bodies. -- Cartesion oval (Geom.), a curve such that, for any point of the curve mr + m'r' = c, where r and r' are the distances of the point from the two foci a…

The upper or lower part of a truss, usually horizontal, resisting compression or tension. Waddell. Accidental, Common, and Vocal chords. See under Accidental, Common, and Vocal. -- Chord of an arch. See Illust. of Arch. -- Chord of curvature, a chord drawn from any point of a curve, in the circle of curvature for tha…

Compression.

f some inherent power or by movement or change in the thing itself, as distinguished from compression.

A violent collision or compression; a crash; destruction; ruin. The wreck of matter, and the crush of worlds. Addison.

Of or performance to the fingers, or to digits; done with the fingers; as, digital compression; digital examination.

troke of the piston; viz., admission, suppression or cutting off, release or exhaust, and compression of exhaust steam prior to the next admission. Geographical distribution, the natural arrangements of animals and plants in particular regions or districts.

, due to the indraught of a storm center passing over Central Europe. The wind, heated by compression in its descent from the mountains, reaches the base, particularly in winter, dry and warm.

ught to be an animal, afterward supposed to be a colony of microscopic algæ. -- Globe of compression (Mil.), a kind of mine producing a wide crater; -- called also overcharged mine. -- Globe daisy (Bot.), a plant or flower of the genus Globularing, common in Europe. The flowers are minute and form globular heads. --…

. Ground cock, a cock, the plug of which is ground into its seat, as distinguished from a compression cock. Knight. -- Ground glass, glass the transparency of which has been destroyed by having its surface roughened by grinding. -- Ground joint, a close joint made by grinding together two pieces, as of metal with eme…

A sudden compression of the air in the mouth, simultaneously with and affecting the sound made by the closure of the organs in uttering p, t, or k, at the end of a syllable (see Guide to Pronunciation, §§159, 189); also, a similar compression made by an upward thrust of the larynx without any accompanying explosive act…

capable of being reduced by force or pressure into a smaller compass or volume; resisting compression; as, many liquids and solids appear to be almost incompressible. -- In`com*press"i*ble*ness, n.

lectric spark (electric ignition, the usual method is gasoline engines, or by the heat of compression, as in the Diesel engine. Gas and oil engines are chiefly of the stationary type. Gasoline engines are largely used for automobile vehicles, boats, etc. Most internal-combustion engines use the Otto (four-stroke) cycle…

le's law (Physics), an expression of the fact, that when an elastic fluid is subjected to compression, and kept at a constant temperature, the product of the pressure and volume is a constant quantity, i. e., the volume is inversely proportioned to the pressure; -- known also as Mariotte's law, and the law of Boyle and…