Accelaraingpump to Acousticabsorption

Accelarating pump to Accumulator
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accelerating charge is injected into the incoming air charge.
Accelerating pump. (Auto. Mech.) A
plunger-type pump attached to the carburetor for the purpose of in­creasing the richness of the mixture and to give a quick "pickup" under load.
Accelerating pump piston. (Auto. . M ech.) The small leather cup washer or hol1ow brass pistop. in the cylin­der of the accelerator pump.
Acceleration. (Mech.) The rate at which the velocity of a moving body increase.
Accelerator. (Auto. Mech.) A me­chanjcal device for regulating the amount of gas mixture which is
fed to the engine, usually operated by the foot. (Plast.) In plastics, a chemical that hastens reaction, par­ticularly one that speeds resin hard­
ening. Also called promoter.
Accelerometer. (Aero.)An instrument for recording, measuring, or indi­cating accelerations.
Accent. (Math.) A mark or marks to distinguish the order or value of similar symbols, as a (read "a prime"), etc.
Accessibilitry. The degree of conve­nient arrangement of parts to per­mit easy adjustment, repair, assem­bling, disassembling, etc.
Accessory. A mechanical part or at­tachment not necessarily a part of the machine with which it is to be used but does make possible a wider range of work or better per­ formance.
Accordion. (Arch.). A type of door or partition, which can be folded, or opened and closed, in a man­ner like the operation of the bel­lows of the musical instrument.
Accumulator. (Mech.) A cylinder into which water is forced in or­der to furnish the motive power
in hydraulic machines of various kinds. (Elec.) A storage battery.
Accurate. Without error; precise; correct; conforming exactly to a standard.
Acetate Base. The transparent cellu­lose acetate plastic film which for years formed the base of backing of magnetic recordillg tape.
Acetate, cellulose. (Plast.) Plastic lIsed as a base for magnetic record­ing tape.
Acetic acid. (Chem.) A colourless, pungent liquid (HC2HP2) usually obtained by the destructive distil­lation of wood or by the oxidation of alcohol with ferments. Vinegar is an impure acetic acid.
Acetone. An inflammable liquid (CH]COOCH]) with a biuer taste, obtained by the destructive distil­lation of certain wood, acetates, and various organic compounds.
Acetylene gas. An illuminating gas (C2~) resulting from the action of water on calcium carbide. Also used for oxyacetylene welding.
Acetylene generator. (Weld.) A con­tainer from which there can be sup­plied, under uniform pressure, the acetylene gas produced by the ac­
tion of water on calcium carbide.
Acetylite. (Chem.) Calcium carbide treated with glucose to give a slower and more uniform produc­tion of acetylene gas than can be had from the untreated calcium carbide.
Achromatic. Without colour. A lens which refracts light of all colours equally is said to be achromatic.
Acid. (I) A substance which produces hydrogen ions when dissolved in water. (2) Acid is a hydrogen com­pound whose aqueous solution contains hydrogen ions and no other positive ions.
Acid bath. (Elec.) Pickle used for cleansing metal objects in prepa­ration for electroplating, usually by dipping.
Acidblast etching. (Prillt.) A proc­ess for the mechanical etching of photo-engraved plates.
Acid colour. (Dyeing) Artificial or­ganic dyestuff, so named from the fact that acid is used as an assist­ant for creating an affinity of the fiber for this dyestuff. About 75 per cent of all wool dyeing is ac­complished by its use.
Acid cure. (Auto.) The use of sul­phur chloride for repairing tires by rapid vulcanization without heat.
Acid-proof paint. (Elec.) Paint which resists the action of acid.
Acidulated water. (Elec.) Any acid solution which is diluted with water.
Acieral. (Metal.) A light weight al­loy, .6.4 per cent copper, 0.4 per cent zinc, 0.9 per cent nickel, 0.1 per cent iron, 0.4 per cent silicon, and the balance aluminium. It was formerly used extensively for au­to~otive parts.
Acme thread (Mech.). A screw thread, the section of which is between the square and V threads. Used extensively for feed screws. The included angle of space is 29 deg. as compared to 60 deg. of the National Coarse or U.S. thread.
Acoustic absorption. The sound dead (absorptive) characteristics of any susbtance. The reference unit of absorption is one Sabin which is equal to the sound "ab­sorbed" by a one square foot open­ing through which sound passes (never to return). In the metric