14. (Paint.) (a) The representation or reproduction of the effect of the atmospheric medium through which every object in nature is viewed. New Am. Cyc. (b) Carriage; attitude; action; movement; as, the head of that portrait has a good air. Fairholt.

15. (Man.) The artificial motion or carriage of a horse. &hand; Air is much used adjectively or as the first part of a compound term. In most cases it might be written indifferently, as a separate limiting word, or as the first element of the compound term, with or without the hyphen; as, air bladder, air-bladder, or airbladder; air cell, air-cell, or aircell; air-pump, or airpump. Air balloon. See Balloon. -- Air bath. (a) An apparatus for the application of air to the body. (b) An arrangement for drying substances in air of any desired temperature. -- Air castle. See Castle in the air, under Castle. -- Air compressor, a machine for compressing air to be used as a motive power. -- Air crossing, a passage for air in a mine. -- Air cushion, an air-tight cushion which can be inflated; also, a device for arresting motion without shock by confined air. -- Air fountain, a contrivance for producing a jet of water by the force of compressed air. -- Air furnace, a furnace which depends on a natural draft and not on blast. -- Air line, a straight line; a bee line. Hence Air-line, adj.; as, air-line road. -- Air lock (Hydr. Engin.), an intermediate chamber between the outer air and the compressed-air chamber of a pneumatic caisson. Knight. -- Air port (Nav.), a scuttle or porthole in a ship to admit air. -- Air spring, a spring in which the elasticity of air is utilized. -- Air thermometer, a form of thermometer in which the contraction and expansion of air is made to measure changes of temperature. -- Air threads, gossamer. -- Air trap, a contrivance for shutting off foul air or gas from drains, sewers, etc.; a stench trap. -- Air trunk, a pipe or shaft for conducting foul or heated air from a room. -- Air valve, a valve to regulate the admission or egress of air; esp. a valve which opens inwardly in a steam boiler and allows air to enter. -- Air way, a passage for a current of air; as the air way of an air pump; an air way in a mine. -- In the air. (a) Prevalent without traceable origin or authority, as rumors. (b) Not in a fixed or stable position; unsettled. (c) (Mil.) Unsupported and liable to be turned or taken in flank; as, the army had its wing in the air. -- To take air, to be divulged; to be made public. -- To take the air, to go abroad; to walk or ride out.

Air