The Savannah morning news. (Savannah, Ga.) 1900-current, 1903-01-31
LIQUID AIR.
Waste I'm Using 1t for Ordinary Cold
stOrREe-UsefuI for Cooling Rooms

Waste in Using 1t for Ordinary Cold
StOrREe-UscfuI for Cooling Rooms
From the London Globe.
A good deal of nonsense has been
written about liquid air, principally in
America. 1t was to be the power of the
future. By it's means power was to be
obtained for nothing, and so on. In
the lecture which he gave before the
Cold Storage Association recently, DIR.
Carl Linde of Berlin did good service
in clearing away a good many mis-
conceptions. 1t would not be economi-
cal to employ it in cold storage work.
he explained, because when you only
require a temperature a few degrees
below the freezing point OF water, it is
not economical to produce a temper
allure 280 degrees Fahrenheit below
Power has to be expended in producing
cold, and the power is roughly pro-
portional to the degree of cold pro-
duced. Liquid air, in small quantities,
the lecturer observed, would be very
useful, say, for cooling dining or ball
rooms, In these cases the quantity OF
liquid air would be so small that the
high price at which it was produced
NOulQ nOL HIdlleT. DRAWINGS were
shown of apparatus by which rooms
could be cooled in this way.
Liquid air is produced from ordinary
atmospheric air by. continuous pro-
cess Of compression and cooling. Every
substance, it is supposed, may exist
in one of three states, the solid, the
liquid or the gaseous, according to the
surrounding conditions. Each state
presupposes the presence of a certain
Thus in the solid form a smaller guam
tity of heat is present, actually in the
substance itself, than in the liquid
form; and again a smaller quantity of
heat is present in the liquid form than
in the gaseous. The addition or the
subtra elton of heat from any substance
in sufficient quantities, will cause the
substance to change its state. In addi-
tion, the three forms in which sub
stances may exist mean that the mole
cules, the very minute parts of the
substances, are very much closer to-
gether in the solid form than in the
liquid form, and in the liquid form
they are much closer together than
in the gaseous form. So that in order
to liquefy gas, two things are neces-
sary, the closing up as it were of its
molecules, and the extraction of GER
tain quantity of heat from 1t. When
air is compressed, as in those cases
where compressed air is used for me-
chanical purposes, heat is generated in
the air in the act of compression.
1t represents a portion of the work
done upon the air, by the compressors.
And this heat has to be extracted, as
we'll as the heat possessed by the air,
in virtue of it's condition as a gaseous
mixture, before 1t can be liquefed.
And so in the process of making Ii
quid air the air is continually COM
pressed by successive stages, and con-
tinuously cooled, a very pretty device
being made use of in the cooling, by
which the air which has been cooled
to a certain degree is made to cool
air that has not reach that point, so
that the effect Is cumulative. When
liquefactfon is finally reached, the air
in it's liquid form looks exactly like
water, and may be poured out. just as
water is-with certain precautions. The
fact that the liquid air is at the ex-
tremely low temperature named makes
it dangerous to handle without pre-
cautions similar to those which are
taken in handling hot bodies. With
very cold bodies heat passes from the
hand, say, to the object at a very
rapid rate, just as heat passes from
a hot body to the hand at a rapid rate.
1t is the rate at which the heat is
transferred, either to or from the hui
man body, which causes the pain and
other troubles When poured out on a
table the liquid air runs about in
small globules, just as mercury does,
and disappears in very short time.
1t has returned to its gaseous form.
When allowed to escape into the at
mosphere, its presence is shown by
clouds of mist, producing the impress
sion that the liquid air is converted
into fog. This is not so. however
What really happens is. the aqueous
vapor which is always present in the