air-hoist 
air-hoist (ar'hoist), n. Hoisting machinery op- 
erated by compressed air, or by the creation of 
a partial vacuum. It consists of a cylinder fitted with 
a piston, which is connected tiy ropes passing over pulleys 
with the platform of the hoist. See elevator and hoist. 
air-holder (ar'hol'der), H. 1 . A vessel for hold- 
ing air for any purpose, as for counteracting 
the pressure of a decreasing column of mercury, 
or for keeping up a moderate and steady cur- 
rent of air. See airometer, air-vessel, and gats- 
AW<T. 2f. A gasometer. 
air-hole (ar'hol), . 1. An opening to admit 
or discharge air. 2. In founding, a fault in a 
casting, caused by a bubble of air which passes 
from the core outward, and ia retained in the 
metal. Also called blmr-hole. 3. A natural 
opening in the frozen surf ace of a river or pond, 
caused by currents or springs. 
airie't (ar'i), a. An old spelling of airy 1 . 
airie'4 (ar'i), . An old spelling of aery 2 . 
airified (ar'i-fid), a. [< *airify, make airy (< 
air 1 (>2) -f. .fyj t -f- -crf2.] Fashioned in an airy 
manner; characterized by the assumption of 
airs: as, an airified style. [Contemptuous or 
slighting.] 
airily (ar'i-li), adv. [< airy 1 + -fy2.] 1. Inan 
airy or gay manner; gaily; jauntily. 
Fanny bade her father good-night, and whisked off 
airily. I>ickeiut, Little Dorrit. 
2. Lightly; delicately: as, airily wrought de- 
tails. 
airiness (ar'i-nes), n. 1. Exposure to a free 
current of air ; openness to the air : as, the air- 
iness of a country-seat. 2. Unsubstantiality, 
like that of air. 3. Delicacy and lightness; 
ethereality. 4. Sprightliness of motion or 
manner; gaiety; jauntiness; vanity; affecta- 
tion : as, the airiness of young persons. 
airing (ar'ing), n. [Verbal n. of air 1 , t'.] 1. An 
exposure to the air, or to a fire, for drying or 
warming. 2. Exercise in or exposure to the 
open air ; an excursion for the purpose of tak- 
ing the air. 
All the virtues seemed to have come out for an airing 
in one chariot. Motley, Dutch Republic, III. 634. 
airing-stage (ar'ing-staj), n. A stage or plat- 
form upon which materials are placed to bo 
aired or dried : as, the airing-stage upon which 
powder is dried. 
air-injector (ar'in-jek*tor), n. A simple blow- 
ing device, used with a dental drill or employed 
for removing dust from the path of a fine saw. 
airisadt, airisardti Same as arisad. 
airisht (ar'ish), . [ME. ayrisshe, ayerissh, 
etc.; < air 1 + -is/i 1 . 1 1. Of or belonging to 
the air; aerial. 
And beheld the ayerisshe bestes. 
Chaucer, House of Fame, 1. 9G5. 
2. Cool; fresh. 
Themorniug8areain's/i. Best, Farming, p. 18. (y.E.D.) 
air-jacket (ar' jak"et), H. A jacket inflated with 
air, or to which bladders filled with air are fas- 
tened, to render the wearer buoyant in water. 
airless (ar'les), a. [< air 1 + -less.'] 1. Not 
open to a free current of air; wanting fresh air 
or communication with open air. 2. Without 
air; devoid of atmosphere. 
Desolate as the lifeless, airless moon. 
Harper's Mag., LXV. 73. 
air-level (ar'lev'el), n. A name sometimes 
given to a spirit-level (which see), 
air-line (ar'lin), . and a. I. n. A line as direct 
as though drawn or stretched through the air ; 
a bee-line. 
II. a. Straight or direct as a line in the air ; 
not deflected laterally: as, an air-line railroad, 
airlingt (ar'ling), w. [< air 1 + -ling 1 .'] Athought- 
less, gay person. 
Some more there be, slight airlings, will be won 
With dogs and horses. B. Jonson, Catiline, i. 3. 
air-lock (ar'lok), n. An air-tight chamber in a 
caisson in which operations are carried on under 
water, communicating by one door with the 
outer air and the main entrance-shaft of the 
caisson, and by another door with the chambers 
filled with condensed air in which the men are at 
work. Its purpose is to regulate the air-pressure so 
that the change from ordinary air to condensed air may 
be made without injury. When a workman steps from 
the shaft into the air-lock the door of ingress is closed, and 
condensed air is admitted until the pressure is the same 
as that in the working-chamber. The process is reversed 
when leaving the caisson. 
air-locomotive (ar'16-ko-mo"tiv), n. A loco- 
motive driven by compressed or heated air, 
usually the former. 
air-logged (ar'logd), a. [< air 1 + logged, after 
water-logged.'] In maeJi., impeded, as motion, 
by the intrusion of air. Thus, a machine consisting 
124 
in part of a piston moving in a cylinder would become 
air-ttKj'ied if air should enter the cylinder and remain 
between the piston and the cylinder-head, so as to pre- 
vent the piston from making its full stroke. 
air-machine (ar'ma-shen"), n. In mining, an 
apparatus by which pure air is forced into parts 
badly ventilated, and the foul air extracted. 
air-manometer (ar'ma-nom*e-ter), n. Same 
as air-gage. See manometer. 
air-meter (ar ' me * ter), n. An apparatus for 
measuring the quantity or rate of flow of air. 
Various devices are used, as bellows, cylinder and piston, 
and rotating buckets, in which capacities are constant, 
and fans and vanes, which measure the rapidity of flow 
through conduits of known sectional area, and therefore 
indicate the quantities passing in any given time. 
aim (am), n. Scotch form of iron. 
airohydrogen (ar'd-hi'dro-jen), a. [< air 1 , 
after aero-, + hydrogen.'] Pertaining to a mix- 
ture of atmospheric air and hydrogen. Airo- 
hydrogen blowpipe. See blowpipe. 
airometer (ar-om'e-ter), n. [< air 1 , after aero-, 
+ Gr. [ifTfwv, measure. Cf. aerometer."] 1. An 
air-holder constructed upon the principle of the 
gasometer, whence the name. See gasometer. 
2. Same as air-meter. 
The airometer, the invention of Mr. Henry Hall, the in- 
spector, by means of a delicately-constructed windmill, 
shows the rate of the current of air in the passages of the 
colliery. Ure, Diet, IV. 890. 
air-passage (ar'pas'aj), . 1. In anat., one of 
the passages by which air is admitted to the 
lungs, as the nasal passages, the larynx, the 
trachea, and the bronchial tubes or their minute 
ramifications. 2. In hot., a large intercellular 
space in the stems and leaves of aquatic plants, 
and in the stems of endogens. 
air-pipe (ar'pip), n. A pipe used to draw foul 
air out of or conduct fresh air into close places. 
Specifically-- (a) A pipe used to draw foul air from a 
ship's hold by means of a communication with the furnace 
and of the rarefaction of the air by the flre. (b) In min- 
ing, a pipe through which air passes, either for ventila- 
tion or for use in an air-engine, (c) A small copper pipe 
leading from the top of the hot-well of a marine engine 
through the side of the vessel, for the discharge of the 
air and uncondensed vapor removed from the condenser 
by the air-pump. 
air-pit (ar'pit), n. A pit or shaft in a coal- 
mine, used for ventilation. Also called air- 
shaft. [Eng.] 
air-plant (ar'plant), n. A plant unconnected 
with the ground and apparently living on air: 
applied to epiphytes, but usually not to para- 
sites. Many epiphytic orchids in cultivation 
are popularly so named. 
air-poise (ar'poiz), n. An instrument used to 
measure the weight of the air. 
air-port (ar'port), n. In ship-building: (a) A 
small aperture cut in the side of a vessel to 
admit light and air. One is generally placed in each 
state-room, and there are several on each side along the 
berth-deck. They are usually nUed so as to close with a 
pane of thick glass, set in a brass frame, turning on a 
hinge, and secured when closed by a heavy thumb-screw. 
(b) A large scuttle placed in a ship's bows for 
the admission of air. Also called air-scuttle. 
air-proof (ar'prof), a. Impervious to air. 
air-pump (ar'pump), n. An apparatus for the 
exhaustion, compression, or transmission of 
air. Air-pumps are used for many purposes, and are 
made in a variety of forms, which differ according to the 
uses that they serve. In the more common forms the 
air is exhausted by means of a cylinder and piston, as in 
Ritchie's air-pump (see cut), or by centrifugal action. Ro- 
tating buckets dipping into 
water, which forms a seal, 
are used for some special 
purposes ; as is also, for 
slight changes of pressure, 
a form consisting of a vessel 
closed at the top and sides 
but open at the bottom, and 
dipping to a certain extent 
into water or other fluid, 
which forms a seal and 
prevents the escape of the 
air. For the Sprengel air- 
pump, see mercury air- 
pump, under mercury. The 
air-pump of a condensing 
steam-engine is used to 
maintain a vacuum with- 
in the condenser by with- 
drawing from it air and 
uncondensed vapor. See 
air-compressor, aspirator, 
ejector, pump, steam-jet. 
Air and circulating 
pump, in a condensing 
steam-engine, a combined 
motor and pump, used as 
an air-pump, and also to 
Ritchie's Air-Pump. 
pump the water from the hot-well into the boilers. Air- 
pump bucket, an open piston with valves on the upper 
surface opening upward so as to admit air and water dur- 
ing the down-stroke, and lift them with the up-stroke, of 
the pump. 
air-pyrometer (ar'pi-rom'e-ter), n. An instru- 
ment used for measuring high temperatures. 
air -trunk 
It consists of a hollow globe made of platinum, so that it 
may resist excessive heat, tilled with air or gas, and con- 
nected with a bent glass tube, which holds at its bend 
water, mercury, < r other liquid. The expansion by heat of 
the air within the globe exerts a pressure upon the liquid, 
causing it to rise in one leg of the tube to a height propor- 
tioned to the expansion, and therefore to the heat which 
causes it. See i>i/n>u/''li'r. 
air-receptacle (ar're-sep"ta-kl), . In ornith., 
a large air-cell ; an air-space, air-sac, or pneu- 
matocyst. 
Continuous afe-TMtpAuftt throughout the binly. <>"< n. 
air-regulator (ar'reg'u-la-tor), . Any appa- 
ratus designed to govern the admission or flow 
of air, as a damper or register. 
air-reservoir (ar^ez^er-vwor), n. See air- 
holder and air-vessel. 
air-sac (ar'sak),. 1. Inom;Wf.,alargeair-frll; 
an air-space, an air-receptacle, or a pneumato- 
cyst; one of the membranous bags or recepta- 
cles of air lodged in the hollow bones and the 
cavities of the body of birds, and communicating 
with the lungs. 2. pi. The elongated cavities 
forming the ultimate branches of the air-pas- 
sages in the lungs of mammals. Also called 
iiifundibula. 
air-scuttle (ar'skut'l), . Same as air-port, (b). 
air-setting (ar'set'ing), a. Setting or harden- 
ing on exposure to air, as common mortar. 
air-shaft (ai-'shaft), n. 1. Same as air-pit. 2. 
Any ventilating shaft. 
air-slaked (ar'slakt), a. Hydrated and disin- 
tegrated by exposure to atmospheric air : as, 
air-slaked lime. 
air-sollar (ar'sol"ar), n. A compartment, pas- 
sageway, or brattice carried beneath the floor 
of a heading or an excavation in a coal-mine, 
for ventilation. See sollar. 
air-space (ar'spas), n. 1. In ornith., an air- 
cell of large size ; an air-receptacle or a pneu- 
matocyst (which see). 2. lamed, and sanitary 
science, the clear cubic contents of a room, as 
the ward of a hospital, with reference to the 
respirable air contained in it : as, air-space per 
man, so many cubic feet. 3. In firearms, a 
vacant space between the powder-charge and 
the projectile. 
air-spring (ar'spring), n. Any device designed 
to resist a sudden pressure, as the recoil of a 
gun, the momentum of a railroad-car, or the 
thrust of the moving parts of a machine, by 
means of the elasticity of compressed air. The 
common form is that of a cylinder containing air which is 
compressed by a piston or plunger. Same as pneumatic 
spring. Also called air-cushion or air-buffer. 
air-stack (ar'stak), n. A chimney used for ven- 
tilating a coal-mine. [Pennsylvania.] 
air-Stove (ar'stov), n. A stove provided with 
flues about the fire-box and chamber, the air 
in which when heated ascends through pipes 
to the apartments to be supplied with warmth. 
See air-furnace and heater. 
air-strake (ar'strak), n. In ship-building, an 
opening left for ventilating purposes between 
two planks of the inside ceiling of a ship. 
airt (art), n. [Also spelled airth, art, arth; < 
Gael, aird, Ard = Ir. ard, a height, top, point, 
a promontory, a point of the compass, esp. one 
of the four cardinal points, a quarter of the 
heavens.] Point of the compass; direction. 
[Scotch.] 
Of a' the airts the wind can blaw, 
I dearly lo'e the west Burns, Song. 
airt (art), v. t. [Also spelled art, ert; < airt, .] 
To direct or point out the way : as, can you airt 
me to the school-house ? [Scotch.] 
air-thermometer ( ar ' ther - mom " e - ter) , n. A 
thermometer in which air is used instead of 
mercury. It has the advantage of being more delicate 
and accurate, and can be employed at any temperature ; 
but it is difficult to use, and hence is employed only in 
physical experiments. It is useful as a standard with which 
the indications of ordinary thermometers may be com- 
pared. Leslie's differential thermometer is a kind of air- 
thermometer. See thermometer. 
air-thread (ar'thred), w. A spider's thread float- 
ing in the air. Also called air-gossamer. 
air-tight (ar'tit), a. So tight or close as to be 
impermeable to air : as, an air-tight vessel Air- 
tight Stove, a kind of sheet-iron stove in which wood is used 
as fuel : so named because, although not literally air-tight, 
it is practically so in comparison with au open fireplace. 
air-trap (ar'trap), . 1. A contrivance for pre- 
venting the access, as to a room, of the effluvia 
arising from drains and sinks. 2. A reservoir 
and escape-valve placed at the joints or higher 
points of a water-main or pipe-line to allow the 
escape of air which may accumulate in the pipes. 
air-trunk (ar'trungk), . A large conduit for 
supplying pure air to, or for removing foul or 
heated air from, theaters, etc. 
