air-carbureter 
air-carbureter (ar'kar"bu-ret-er), n. An ap- 
paratus in which air is passed through or over 
the surface of liquid hydrocarbons, and thus 
becomes charged with inflammable vapor. 
See gas-macMne. 
air-casing (ar'ka"sing), . An air-tight casing 
of sheet-iron placed around a pipe to prevent 
undue transmission of heat or cold ; specifically, 
the casing placed around the base of the funnel 
or smoke-stack of a steamship, to prevent too 
great a transmission of heat to the deck. 
air-castle (ar'kas"l), . A castle in the air; a 
day-dream; a visionary scheme. See castle. 
Adventures, triumphs of strength and skill these fur- 
nish subject-matter for the talk of the uncivilized man 
and the air -castle a of the youth. 
//. Speiuxr, Prin. of Psycho!., 4S2. 
air-cavity (ar'kav"i-ti), . A cavity contain- 
ing air ; specifically! such a cavity occurring in 
the body or bones of an animal ; a large air- 
sac or pneumatocyst of a bird. 
In the latter case, air-cavities take the place of the 
medulla, which disappears, and so diminish permanently 
the specific gravity of the animal. 
f. 1 ' 'fuhaur, Comp. Anat. (trans.), p. 573. 
air-cell (ar'sel), . 1. In bot., one of the cav- 
ities in the leaves, stems, or other parts of 
plants, containing air. They are 
well seen in the bladders of seaweeds, and 
are found in other aquatic plants, which 
they serve to float. 
2. Inanat. and ^oo7., a definite cir- 
cumscribed cavity in the body, 
containing atmospheric air in- 
haled through air-passages which 
place it in direct communication 
with the outer air. The term is used 
for any such cavity, without reference to 
the technical meaning of cell (which see). 
An air-cell is generally of small size, if 
not microscopic, as one of those in lung-tissue; but it 
sometimes forms a great space or inflatable inclosed area, 
as the air-cells of birds, and is then also called air-space, 
air-receptacle, or pneumatocyst. Specifically (a) One of 
the small hemispherical saccules which beset the walls of 
the alveolar passages and infundibula of the lungs. Also 
called alveolus, (b) One of the dilatations of the trachea 
or air-tube in insects forming the respiratory apparatus. 
(c) In ornith., a pneumatocyst; any one of the extra-pul- 
monary cavities of the body of a bird, containing air, which 
are continuous with one another and with one or more of 
the bronchial tubes. See pneumatocygt. 
air-chamber (ar' chain 'ber), n. 1. A large 
cavity in an organic body containing air. 
2. A compartment of a hydraulic engine or 
apparatus, as a pump, interposed 
between and connected with the 
supply- and delivery-passages, and 
containing air which by its elas- 
ticity equalizes the pressure and 
flow of the fluids. Thus, in a recipro- 
cating force-pump, the impulse given to 
the fluid by the delivery-stroke compresses 
the air in the air-chamber, and this com- 
pressed air reacts upon the outflowing fluid 
to continue ita motion during the reverse 
stroke, or during those intervals when the 
force imparted falls below the average or 
Air-chamber, normal amount. The pressure and flow are 
thus made practically uniform, notwith- 
standing the intermittent or variable action of the force. 
For some special forms, see air-vessel. 
3. Any compartment or chamber designed to 
contain air: as, the air-chamber of a life-boat. 
air-chambered (ar'cham"berd), a. Furnished 
with an air-chamber or with air-chambers. 
It [the life-boat] was air-chambered and buoyant. 
Kane, Sec. Grinn. Exp., I. 49. 
air-cock (ar'kok), n. A cock used to control 
the admission or outflow of air. See cock 1 , 8. 
air-compressor (ar'kom-pres'qr), n. A ma- 
chine for condensing air, usually in the form of 
a force-pump. See compressor. 
air-cone (ar'kon), n. A cone in a marine en- 
gine designed to receive the gases which enter 
the hot-well from the air-pump, and carry them 
off through a pipe at the top. 
air-cooler (ar'k6' f ler), n. Any appliance for 
lowering the temperature of the air, as in hos- 
pitals, dwellings, and theaters. A common form 
consists of chambers filled with ice, or fitted with screens 
of light fabric kept constantly wet with cooling liquids, 
through which a current of air is forced. See refrigerat- 
iu<r-ch<imber, under refrigerate. 
air-course (ar'kors), n. A passage in a mine 
made or used for ventilating purposes ; an air- 
way. 
air-crossing (ar'kr6s"ing), . A passageway 
or bridge constructed to carry one air-course 
over another, as in the ventilation of coal-mines. 
air-CUShion (iir'kush'on), n. 1. A bag made 
of an air-tight fabric used when inflated with 
air as a cushion for a seat. 2. Same as air- 
bag. 3. A ball or cylinder (usually of india- 
rubber) filled with air and placed in a water-pipe, 
123 
to act as a cushion for the water, or to receive 
the pressure or shock caused by a sudden stop- 
page of its flow, or by the expansion of the 
water in freezing. 4. Same as air-spring or 
pneumatic spring. 
air-cylinder (ar'sil'in-der), n. In gun., a de- 
vice consisting of a cylinder and piston, used 
for checking the recoil of heavy guns by means 
of the elasticity of atmospheric air confined 
within it ; a pneumatic buffer. 
air-dew (ar'du), n. Manna. [Rare.] 
air-drain (ar'dran), n. 1. An empty space left 
around the external foundation-walls of a build- 
ing to prevent the earth from lying against 
them and thus causing dampness. 2. In mold- 
ing, a large passage for the escape of gases 
from heavy castings while in the mold. 
air-drawn (ar'dran), a. Drawn or depicted in 
the air: as, "the air-drawn dagger," Shak., 
Macbeth, iii. 4. 
air-dried (ar'drid), a. Dried by or in the air: 
applied to fruits and materials from which 
moisture has been removed by exposure to 
currents of air under natural atmospheric con- 
ditions. 
air-drill (ar'dril), n. A rock-drill driven by 
compressed air, as distinguished from a drill 
driven by steam. See rock-drill. 
air-drum (ar'drum), n. A drum-shaped cham- 
ber or reservoir for air; specifically, in ornith., 
a large lateral cervical pneumatocyst. 
The great air-drums of our pinnated grouse and cock- 
of-the-plains. Cvues, Key to N. A. Birds, p. 200. 
air-duct (ar'dukt), n. A duct or passage con- 
veying air; specifically, in ichth., the commu- 
nication of the air-bladder with the intestinal 
canal. It is persistent in physostomous, tem- 
porary in physoclistous, fishes. 
aire 1 !, n. An old form of aery 2 . 
aire a (i're; mod. pron. ar), n. [Ir., pi. airig; 
cf. aireach, a noble, a privileged person.] In 
Irish antiq., a freeman; a gentleman; one of 
the privileged classes. Aires were of two classes : (a) 
the flatlu, or those who possessed property in land ; and 
(6) the bo-airett, who possessed cows and other chattels. 
The king was elected by these two classes. 
Clansmen who possessed twenty-one cows and upwards 
were airig (sing, aire), or, as we should say, had the fran- 
chise, and might fulfil the functions of bail, witness, etc. 
Encyc. Brit., XIII. 287. 
The upper classes were all airts. To be eligible to the 
aire grade, the freeman should possess, besides a certain 
amount of wealth in cattle, a prescribed assortment of 
agricultural implements and household goods. 
Encyc. Brit., IV. 252. 
air-endway (ar'end'wa), n. A roadway or 
level driven into a coal-seam parallel with a 
main level, used chiefly for purposes of venti- 
lation. Gresley. [TEng.] 
air-engine (ar'en'jm), . A motor employing 
(a) the elastic force of air expanded by heat, 
air-heading 
air-equalizer (ar'e"kwal-i-zer), x. A device for 
distributing a current of air equally throughout 
its working-space. 
airer (ar'er), n. [< flM-l, v., + -erl.] 1. One 
who airs or exposes to the air. 2. A screen 
for drying clothes, etc. 
air-escape (ar'es-kap*), n. An air-trap for the 
escape of air whicli collects in the upper bends 
of water-pipes and in other hydraulic apparatus. 
The usual form is that of a ball-cock (which see) inclosed 
in a chamber situated at the point at which the air is to 
be withdrawn, and so adjusted that as the water-level 
within is lowered by the pressure of the accumulated air 
the ball-float descends, opens the valve, and penults the 
air to escape ; the water then rising buoys up the float 
and closes the valve. 
air-exhauster (ar'eg-zas'ter), n. 1. Same as 
air-escape. 2. Any apparatus, as an air-pump, 
exhaust-fan, suction-blower, or steam-jet, used 
for withdrawing air from an inclosed place, for 
ventilation or for the creation of a vacuum. 
See air-pump, blower, fan, and ventilator. 
air-faucet (ar'fa/set), n. A stop-cock for let- 
ting air out or in. 
air-filter (ar'fil"ter), n. An apparatus for ex- 
tracting dust, smoke, microscopic germs, etc., 
from the air. It consists of screens or strainers of 
woven-wire fabrics, gun-cotton, asbestos, slag-wool, or 
other flocculent material, through which the air is drawn ; 
or of showers, sprays, or films of water or chemical solu- 
tions, through or over which the air to be filtered passes. 
Air-niters are used in the ventilation of buildings and rail- 
road-cars, in physical research, in surgery, and in the re- 
covery of by-products in manufactures. 
air-flue (ar'flo), n. A conduit for air. See air- 
box, air-funnel, and air-pipe. 
air-fountain (ar'foun'tan), n. An apparatus 
for producing a jet of water by the elastic force 
of air compressed in a close vessel and made to 
act on the surface of the water to be raised. 
air-funnel (ar'fun"el), n. In ship-building, a 
flue formed by the omission of a timber in the 
upper works of a vessel, and designed to pro- 
mote the ventilation of the hold. 
air-furnace (ar'fer"nas), . 1. A reverbera- 
tory furnace (which see, under furnace). 2. 
An air-heating furnace for warming apart- 
ments. Air is led into a space formed between an outer 
easing and the sides of a fire-pot and combustion-cham- 
ber, and, after becoming heated by contact with the walls 
of the latter, flows to the apartments which are to be 
warmed. See air-stove, furnace, and heater. 
air-gage (ar'gaj), n. An instrument for indi- 
cating the pressure of air or gases. It consists of 
a glass tube of uniform caliber, closed at the top and hav- 
ing its lower end dipped into a cup of mercury on the sur- 
face of which the air or gas presses, thus forcing mercury 
into the tube, and compressing the air within it to an 
amount directly proportioned to the pressure. This pres- 
sure can be read from a scale attached to the tube, the 
zero of the scale being usually placed at the upper sur- 
face of the mercurial column when the instrument is ex- 
posed to the ordinary atmospheric pressure. Also called 
air-manometer. 
air-gas (ar'gas), . An inflammable illuminat- 
ing gas made by charging ordinary atmospheric 
air with the vapors of petroleum, naphtha, or 
some similar substance, as the hydrocarbon 
called gasolene. 
air-gate (ar'gat), . 1. An underground road- 
way in a coal-mine, used chiefly for ventilation. 
[Eng. Midland coal-fields.] 2. In molding, an 
orifice through which the displaced air and the 
gases which are formed escape from the mold 
while the molten matter is filling it. 
air-gossamer (ar'gos"a-mer), . Same as air- 
thread. 
air-governor (ar'guv"er-nor), n. A device, at- 
tached to pneumatic apparatus and machinery, 
for regulating the pressure or delivery of air. 
air-grating (ar'gra/ting), n. A grating pro- 
tecting or forming a ventilating orifice in a 
wall or partition. See air-brick. 
air-gun (ar'gun), n. A gun in which condensed 
air is used as the propelling agent. The bore of the 
barrel is connected with a reservoir inclosed within or at- 
tached without the stock, into which air is forced by a 
piston or plunger fitted to the bore, or by an independent 
Ericsson's Hot-air Pum ping-engine. 
a, beam ; *, air-piston ; c , transfer-piston ; rf, cylinder ; _/, air-piston 
link ; *, bell-crank ; o, side-rods ; p, transfer-piston rod ; r, pump ; j, 
air-chamber; f, vacuum-chamber; it, gas-furnace; v, fas-burners; 
if, gas-chamber ; x t water-jacket 
or (6) air compressed by means of another and 
separate motor, called a compressor, which is 
generally a steam-engine. Machine-drills, in min- 
ing, are generally run by compressed-air engines, the com- 
pressor lieing located at the surface, and the air-engines 
distributed underground, at the various points where 
their work is required. 
Air-gun. 
condenser. When the trigger is pulled it operates a valve 
which permits the sudden escape of the whole or of a por- 
tion of the condensed air into the barrel at the rear of 
the ball or dart, thus projecting the latter. In some 
forms the propelling agent is a compressed spring freed 
by the trigger. The reactive force of the spring com- 
presses the air which interposes between it and the pro- 
jectile, and the air acts upon and projects the ball. 
air-heading (ar'hed'ing), . An excavation in 
a mine through which air is made to pass for 
ventilation. 
