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A I R 
AIRLESS, adj. Wanting communication with the free 
air: 
Nor ftony tower, nor walls of beaten brafs, 
Nor airlefs dungeon, nor ftrong links of iron, 
Can be retentive to the ftr.ength of fpirit. Shakefpeare. 
AIRLING,yi [from air, for gayetyf A young, light, 
thoughtlefs, gay, perfon. 
AIR-PIPES, f. an invention for drawing foul air out of 
fhips, or any other ciofe places, by means of fire. Thefe 
pipes were invented by Mr. Sutton, a brewer in London; 
and from him have received the name of Sutton's Air-pipcs. 
The principle on which their operation depends is known 
to every body, being indeed no other than that air is ne- 
ceffary for the fupport of fire; and, if it has not accefs 
from the places mod adjacent, will not fail to come from 
thofe that are more remote. Thus, in a common furnace, 
the air enters through the afh-hole; but, if this is clofed 
up, and a hole made in the fide of the furnace, the air 
will rufh in with great violence through that hole. If a 
tube of any length whatever is inferted in this hole, the 
air 'will rufh through the tube into the fire, and of confe- 
quencc there will be a continued circulation of air in that 
place where the extremity of the tube is laid. Mr. Sut¬ 
ton’s contrivance then, as communicated to the Royal So¬ 
ciety by Dodlor Mead, amounts to this:—“ As, in every 
fhip of any bulk, there is already provided a copper or 
boiling-place proportionable to the fize of the velfel; it is 
propofed to clear the bad air, by means of the fire already 
ufed under the laid coppers or boiling-places for the ne- 
ceffary ufes of the ihip. 
“ It is well known, that, under every fuch copper or 
boiler, there are placed two holes, feparated by a grate; 
the firfit of which is for the fire, and-the other for the allies 
falling front the fame; and that there is alfo a flue from 
the fire-place upward, by which the fmoke of the fire is dif- 
charged at fome convenient place of the fhip. It is alfo 
well known, that the fire once lighted in thefe fire-places, 
is only preferved by the conftant draught of air through 
the fore-mentioned two holes and flue; and that, if the 
faid two holes are clofely flopped up, the fire, though 
burning ever fo brifkly before, is immediately put out. 
“ But if, after fhutting up the above-mentioned holes, 
another hole be opened, communicating with any other 
room or airy place, and with the fire, it is clear, the faid 
fire muft again be raifed and burn as before, there being 
a like draught of air through the fame as there was before 
the flopping up of the firft holes; this cafe differing only 
from the.former in this, that the air feeding the fire will 
now be fupplied from another place. It is therefore pro¬ 
pofed, that, in order to clear the holds of fhips of the bad 
air therein contained, the two holes above-mentioned (the 
fire-place and the afh-place) be both clofed up with fub- 
flantial and tight iron doors; and that a copper or leaden 
pipe, of fuflicient fize, be laid from the hold into the afh- 
place, for the draught of air to come in that way to feed 
the fire. And thus it feems plain, from what has been 
already faid, that there will be, from the hold, a conftant 
difeharge of the air therein contained ; and confequently, 
that the air, fo difeharged, muft be as conftantly fupplied 
by frefh air down the hatches or fuch other communica¬ 
tions as are opened into the hold ; whereby the fame muft 
be continually frefliened, and its air rendered more whole- 
fome and fit for refpiration. And if into this principal 
pipe fo laid into the hold, other pipes are let in, commu¬ 
nicating refpe&ively either with the well or lower decks; 
it muft follow, that part of the air, confumed in feeding 
the fire, muft be refpedtively drawn out of all fuch places 
to which the communication fhall be fo made.” 
This account is fo plain, that no doubt can remain con¬ 
cerning the efficacy of the contrivnnce : it is evident, that, 
by means of pipes of this kind, a conftant circulation of 
frefh air would be occafioned through thofe places where 
it would otherwife be moft apt to ftagnate and putrefy. 
Several other contrivances have been ufed for the fame 
A I R 
purpofe; and Doctor Hales’s ventilators, by fome unac¬ 
countable prejudice, have been reckoned fuperior in effi¬ 
cacy and even limplicity to Mr. Sutton’s machine, which 
at its firft invention met with great oppofition, and even 
when introduced by Dr. Mead, who ufed all his intereft 
for that purpofe, was fhamefully negledted. 
A machine capable of anfwering the fame purpofe was 
invented by M. Defaguliers, which he called the flip's 
lungs. It confifted of a cylindrical box fet up on its edge, 
and fixed to a wooden pedertal. From the upper edge of 
the box iflued a fquare trunk open at the end, and com¬ 
municating with the cavity of the box. Within this box 
was placed a cylindrical wheel turning on an axis. It was 
divided into twelve parts, by means of partitions placed 
like tire radii of a circle. Thefe partitions did not extend 
quite to the centre, but left an open fpace of about eigh¬ 
teen inches diameter in the middle; towards the circum¬ 
ference, they extended as far as poifible without interfe¬ 
ring with the cafe, fo that the w heel might always be al¬ 
lowed to turn freely. Things being thus circumftanced, 
it is plain, that, if the wheel was turned towards that fide 
of the box on which the trunk was, every divifion would 
pufh the air before it, and drive it out through the trunk, 
at the fame time that frefh air would come in through the 
open fpace at the centre, to fupply that which was thrown 
out through the trunk. By turning the wheel fwiftly, a 
ftrong blaft of air would be continually forced out through 
the fquare trunk, on the fame principles on which a com¬ 
mon fanner winnows corn. If the wheel is turned the 
oppofite way, a draught of air may be produced from the 
trunk to the centre. If this machine, then, is placed in a 
room where a circulation of air is wanted, and the trunk 
made to pafs through one of the walls; by turning the 
wheel fwiftly round, the air will be forced with great ve¬ 
locity out of that room, at the fame time that frefh air 
will enter through any chinks by which it can have accefs, 
to fupply that which has been forced out. 
It is evident, that the circulation which is promoted by 
this machine, is entirely of the fame kind with that pro¬ 
duced by Mr. Sutton’s; the turning of the wheel in M. 
Defagulier’s machine being equivalent to the rarefaction 
of the air by fire in Mr. Sutton’s: but that the hitter is 
vaftly fuperior, as adding of itfelf, and without intermif- 
fion, requires no arguments to prove. Mr. Sutton’s ma¬ 
chine has yet another conveniency, of which no other 
contrivance for the fame purpofe canboaft; namely, that 
it not only draws out putrid air, but deftroys it by caufing 
it to pafs through fire; and experience has abundantly 
ftiewn, that though putrid air is thrown into a great quan¬ 
tity of frefh air, it is fo far from lofing its pernicious pro¬ 
perties, that it often produces noxious difeafes. We do 
not fay, indeed, that putrid air becomes falutary by this 
means : but it is undoubtedly rendered lefs noxious than 
before; though, whether it is equally innocent with the 
fmoke of a fire fed in the common way, we cannot pretend 
fo determine. 
Befides this machine by M. Defaguliers, the ventilators 
of Dr. Hales, already mentioned, and thofe called wind- 
fails, are likewife ufed for the fame purpofe. The former, 
of which is an improvement of the Heffian-bellows: the 
other is a contrivance for throwing frefh air into thofe 
places where putrid air is apt to lodge; but this has the 
lad-mentioned inconvenience in a much greater degree 
than any of the others, as the blaft of frefh air throws out 
that which was rendered putrid by ftagnation, in fuch a 
manner as to contaminate all around it. See Wind-sails. 
Air-pump, in pneumatics, is a machine for exhauft- 
ing the air out of a proper veftel, and fo to make what is 
commonly called a vacuum; though in reality the air in 
the receiver is only rarefied to a great degree, fo as to take 
olf the ordinary effects of the atmofphere. So that by 
this machine we learn, in fome meafure, what our earth 
would be without air; and how much all vital, genera¬ 
tive, nutritive, and alterative, powers, depend upon it. 
The principle on which the air-pump is conftrucled, is 
the 
