Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1898-06-16
LIQUID AIR.
Interesting Facts About This Newest Won.
dor of Applied SCIENCE.
fhartaa r rri,tar /, tha ftn.,nn,.nllt..

| anhrlsb r. iFlllor III inc NostnOpoltan.
Liquid air is simply air such ss we
breathe. from which most OF the heat,
originally derived from the sun, has
been extracted. This am now able
to effect very easily and cheaply. by
mechanical means which will be ex-
planned later. AS a result, some is
minutes after the process is started, q
clear, frosty. looking liquid begins to
pour down from tube about an inch
IN diameter. and speedily fills tue re-
ceptacle placed boneath to receive IL.
This rate OF production can DO main
tanned all day N desirsd Each uuhic
foot of liquid represents nearly 500
cubic feet OF Ordinary air, and 10 Its
expansion az il returns to its gaseous
state lies power of the highest efii-
cheney, easy to control, ready to be
harnessed and utilized lis tompera-
ture, as already stated, ia about 3l2
degrees below zero, Fahrenheit.
If tumbler be filled with the liquid
| it boils vigorously, absorbing portion
of the heat around 1t, and at the end Of
half an hour has completely disap-
peared, indistinguishably mingled with
the air around us, from which IL differs
only in its greater purity. The tumbler,
meanwhile, has become thiokly coated
with frost. II, however,, the liquid be
placed in glass bulb, set inside q
| larger bulb, with half.inch space
between the two from which tha air
has been exhausted, 1t Ia SO protected
by this vacuum jacket that it yaporizes
very slowly, lasting for q number Of
hours.
In this more quiet state ii has the
appearance OF pure water, except that
1t shows a pale blue tint, which in-
teusibes as the evaporation proceeds.
| There are, in fact, twu entirely distinct
fluids present--liqueiieh nitrogen and
liquetied oxygen. II is to the lattor that
the blue tint 10 due, nitrogen being alb
solutely impid.
Fnr transportation far only for
experimental usu-I place the LIQUID In
a large tin can, or cylinder, holding
from three to six gallons. This / wrap 1
with layer of felt, and for protection y
against rough usage, set it inside q
slightly larger eau OF tina same sort.
Over the top lay thick cushion Of
hair.felt. which keeps out heat with.
out preventing free escape OF the ex-
panding gases. With this simple ar
rangement | have kept the liquid for
81 hours, and have shipped II from Nav
York to Washington and TO Boston.
There 10 no difficulty nUr danger 10
handling 1t, provided reasonable pre-
caution is used and the gases are not Z
confined. 1t can be dipped up with a K
tin cup and poured into almost any sort 4
OF dish, like 30 much water. IL you 3
chance to drop the dippar. however, it K
viii snatter like thin glassware. 1t is 4
curious fact that this intensity of
cold makes iron and steel extremely (
brittle, while 1t increases their tensile /
strength. This condition is only tam
porary of course. Copper, gold, silver,
aluminium, PLATINUM and most othed
metals are not 40 Affected. Neither is
Extraordinarily, for its upe 10 valves
whure II Is exposed to great cold, i
important; but rubber becomes aS
friable as go much terra Gotta.
l will now give n brief description Ut
a few OF the most interesting OF thsE
experiments illustrsting the qualities
of this extraordinary fluid.
First, / pour quantity into q hasin.
Thrust your hand into it. No, am
not Joking. You can touch it With psr-
feot impunity, provided you withdraw
your hand Instantly; you will only ex.
perience slight sensation of coulness
In precisely the same way, you mightB
plunge your fingar for fraction nj
second into pot OF molten metal with.
out harm, provided the finger wers
moist. In both casea the ruHsop is the n
same: thin cushion Of vApnr is
formed next the flesh. which for
mument encases and protscts ii like
glove--only here the vapor ia air, and
tho heat that liberates it comes from
your finger But don't be too lelibaratsI
III your movements, for a pause would
mean rost-hite at least. ! have re.
81 -
ouence OF treating liquefed air with
undue familiarity, and such injuriea
heal very slowly.
You will observe thut your hand re.
mains perfectly dry tba LIQUID loes not
adhere TO u. This is as fortunate az it
10 unexpected-for IL 1t wet your flesh
As water docs. the slightest contact
would be disastrous II | throw email X
portion upon your coat sleeve, the cloth
is not moistened, but 10 30 chilled
that 1t becomes white with frost. An
oyster dipped for a moment in howl
Of the liquid becomes as cold as II it
had Nremainad 10 refrigerator fG
hours. This makes very pretty dinner
table experiment.; but II you leave the
toothsome morsel immersed too long, Il
becomes as hard aa the shell from
which ii was extracted. Raw beeisteas
hiny Ho lIuzou Until u flugH, Wnen n
struck, like a piece OF bell-metal
While in this condition, 1t may be
broken Into fragments with q BANNER
and pounded into powder. Butter %
similarly treated. may be reduced to al
line, dry dust; fruit and eggs may be
pulrerized IN the same manner. M
But these are substances that may he
frozen, though not to the Same brittls "
hardness. by tho ordinary cold OF "A
winter. Let US now try something more
refractory. Mercury remains liquid at
all familiar temperatures. but solidiies
at about 40 degrees below zero | place
half pint of it in a papar mold. and
pour over the surface q quantity OF
llquefiod air, The quicksilver, . for
ffeiting all claim to its MANS, is soou
frozen into n rigid bar, resem bling
block OF tin, but so cold that II would
almost blister your flesh 10 touch it. M
~ each end of the mold WIS inserted
largo aorew.eye, aud both these are M
now firmly fixed 10 the hardened meta. 4A
To one OF thuse eyes attach q cord, 4N
and suspend tie bar like a plummet;
to tbs other eye faRten a weight Of, 4
say, 80 pounds. Fifteen or 20 minutes
will elapss heforo the mass is sufficiently 81
thawed to allow the weight to pull out
one OF the screw eyes, when il falls TO
the floor with sudden crash 4. will
be fully half an hour before the meta
4 t.. q