Armature shaft to Asphaltum.

Armature shaft to Artificial magllet
central member of a motor or gene­rator are assembled.
Armature slots. (Elec.) Armature pockets or chambers which admit the windings of a coil.
Armature spider. (Elec.) The radial armed frame which supports the armature of a motor or generator on its shaft.
Armature varnish. (Elec.) An insu­lating varnish used for coating the armature windings as a protection against moisture.
Armature winding. (Elec.) See Coil.
Armoire. (Furn.)A large wardrobe or cupboard during and after. the Renaissance.
Armored cable. (Elec.) Insulated wires within a flexible metallic cov­ering; commonly called B.X.
Arrangement. Settlement, adjust­ment, classification.
Arras. A tapestry. A screen or hang­ings of heavy cloth for the wall of a room.
Arrester. (Mech.) Any mechanical contrivance or device used to stop or slow up motion.
Arresting gear. (Aero.) The gear in­ corporated in aircraft which engages the arresting gear in landing.
Arris. (Arch.) The ridge between two channels of a doric column.An external angle edge ar ridgeArrowheads. (Draft.) The tips at the extremities of dimension .Iines to indicate the exact location to which the measurement refers.
Arsenal process. (Metal.) This hot­dip process for tinning is as fol­lows: The steel plate to the tinned is first pickled in a bath of sul­ph uric acid and water, then washed clean. It is next dipped in a flux of zinc and hydrochloric acid, and rhen dipped in a molten mixture 80-pe:r-cent lead and 20-per-cent tin until well coated.
Arsenic. (Chern.) A silvery, crystal­line metalloid, sometimes found native. It is obtained by the distil­lation of roasted arsenic ores. It is used for medicines, insectisides, arsenic salts, and metallurgy.
Articulatedtype connecting rod. (Auto. Mech.) A type of rod used on V, Y, X, or radial engines in which the crank end of the rods is joined to a master rod.
Artificer. A workman of inventive mind skilled in the use of hand tools.
Artificial. Not genuine or natural; unreal.
Artificial horizon. (Aero.) (1) A de­vice that indicates the altitude of an aircraft with respect to the true horizon. (2) A substitute for a natu­ral horizon, such as a liquid level, pendulum, or gyroscope, incorpo­rated in a navigating instrument.
Artificial magnet. (Elec.) A magnet which has an acquired magnet­ism, as distinguished from a natu­ral magnet.
Artificial stone. A manufactured product made to resemble stone. A common type is made. from pulverized quarry refuse mixed with cement.
Artillery-type wheel. (Auto. Meeh.) The commonly used woodspoke wheel with metal hub and felloe.
Artisan. One who works with his hands and manufactures articles in metal, wood. etc.
Art metal. (Paint.) A silicate of mag­nesium much useq in' paint. It serves as an aid in, holding paint pigment in solution and in bind­ing paint films together. Also mar­keted under such names as "French chalk" and "talc."
Asbestos. A fibrous variety of amphibole distinguished by its abi-lity to resist high temperatures and the action of acids, and capable of being spun and woven. Most of the commercial asbestos comes from Canada. It is used for fireproof clothing, theater curtains. building materials, brake linings, etc.
Asbestos shingles. (Bldg,) A fireproof roof covering made in the form of shingles; asbestos is the principal part of its composition.
Ascender. (Print.) That part of a lower-case letter which extends above the body of the letter as in b, d, h, etc.
Ash. That portion of the mineral sub­stances in coal which remains after the combustible has been burned;
11 is the inorganic substance in the coal and has no heating value. (Wood.) A light-coloured, coarse­grained wood used frequently for the spokes in and felloes of wheel, for hammer handles, and gener­ally in work requiring flexibility combined with moderate strength.
Ashing. (Plastics.) A grinding proc­ess accomplished by means of a buffing wheel coated with a coarse abrasive.
Ashlar. ( (:arp.) Plaster studs between floor beams and rafters of a garret. (Masonry) Dressed stone used for the outside facing of a wall.
Aspect. ratio. The ratio of span to mean chord of an airfoil; i.e., the ratio of the square of the maxi­mum span to the total area of an airfoil.
Aspen. (Wood.) A common tree in many parts of the United. States. The wood is of little commercial importance except for making paper pulp in which it ranks next to spruce and hemlock. Grows to height of 40 to 50 ft.; wood light in colour; brittle; weight 25 pounds per cu.ft.
Asphalt. (Min.) Mineral pitch; a bi­tuminous composition used for paving, flooring, roofing, etc.
Asphalt oil. (Chern.) Oil containing asphalt or having an asphalt base, as distinguished from oil having a paraffin base.
Asphaltum. (Min.) A mineral pitch. It is a form of bitumen, black or brown in color, brittle .and glossy. Asphalt and asphaltum are inter­changeable terms. Principal