Search the Dictionary

A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the interior of a closed vessel, which has been exhausted to a high or the highest degree by an air pump or other artificial means; as, water boils at a reduced temperature in a vacuum.…

A machine for cleaning carpets, tapestry, upholstered work, etc., by suction.

eity. In its recoil from the gross anthropopathy of the vulgar notions, it falls into the vacuum of absolute apathy. Hare.

The part of a vacuum tube opposite the cathode. Upon it the cathode rays impinge.

railway, one in which pneumatic power, obtained from compressed air or the creation of a vacuum, is the propelling force. -- Atmospheric tides. See under Tide.

ld by any other path. This curve of quickest descent, as it is sometimes called, is, in a vacuum, the same as the cycloid.

A globule of air, or globular vacuum, in a transparent solid; as, bubbles in window glass, or in a lens.

posed to anode. Faraday. Cathode ray (Phys.), a kind of ray generated at the cathode in a vacuum tube, by the electrical discharge.

The dark space within the negative-pole glow at the cathode of a vacuum tube, observed only when the pressure is low enough to give a striated discharge; -- called also Crookes layer.

A vacuum tube in which the exhaustion is carried to a very high degree, with the production of a distinct class of effects; -- so called from W. Crookes who introduced it.

A cupping glass or other vessel or instrument used to produce the vacuum in cupping. Cup and ball, a familiar toy of children, having a cup on the top of a piece of wood to which, a ball is attached by a cord; the ball, being thrown up, is to be caught in the cup; bilboquet. Milman.- Cup and can, familiar companions.…

The operation of drawing blood to or from the surface of the person by forming a partial vacuum over the spot. Also, sometimes, a similar operation for drawing pus from an abscess. Cupping glass, a glass cup in which a partial vacuum is produced by heat, in the process of cupping. -- Dry cupping, the application of a…

of steel, on the polarization of an electrolytic cell, or on the electric condition of a vacuum has been applied in the various cymoscopes.

withdrawing air from a space. Ejector condenser (Steam Engine), a condenser in which the vacuum is maintained by a jet pump.

The state of being empty; absence of contents; void space; vacuum; as, the emptiness of a vessel; emptiness of the stomach.

the positions of the object and its image are interchangeable. -- Focus tube (Phys.), a vacuum tube for Roentgen rays in which the cathode rays are focused upon the anticathode, for intensifying the effect. -- Principal, or Solar, focus (Opt.), the focus for parallel rays.

rost bearer (Physics), a philosophical instrument illustrating the freezing of water in a vacuum; a cryophous. -- Frost grape (Bot.), an American grape, with very small, acid berries. -- Frost lamp, a lamp placed below the oil tube of an Argand lamp to keep the oil limpid on cold nights; -- used especially in lightho…

s of steam, or the degree of rarefaction produced in the receiver of an air pump or other vacuum; a manometer. -- Sliding gauge. (Mach.) (a) A templet or pattern for gauging the commonly accepted dimensions or shape of certain parts in general use, as screws, railway-car axles, etc. (b) A gauge used only for testing o…

system. It was intended to be exactly, and is very nearly, equivalent to the weight in a vacuum of one cubic centimeter of pure water at its maximum density. It is equal to 15.432 grains. See Grain, n., 4. Gram degree, or Gramme degree (Physics), a unit of heat, being the amount of heat necessary to raise the temperat…

e with metallic electrodes nearly in contact so as to exhibit the insulating effects of a vacuum. It was used by the German physicist W. Hittorf (b. 1824).