The mirror. (Stillwater, Minn.) 1894-1925, 1906-08-09

of energy to be drawn upon as re- t
quired, renders It commercially value 8
less as such an agent. G
OF course it is not to be understood {
that the expansive power of liquid air I
is absolutely lrresistible-it is not-a I
sphere Of fawless steel having wall q
of uniform thickness of about eight l
inches would Withstand the pressure [
from q cubic inch of the liquid if con-
fined in the center of the sphere, and
it would also be theoretically possible
to retain the liquid incorporated in
even very fragile receptacle could
that receptacle but be suspended,
without external, heat-conducting
supports, in perfect manner.
The problem of the confinement ie,
however, but one of the difficulties
confronting the scientists and engi-
neers who are even still striving for
it's solution. Another serious obsta-
Gle in the path of its utility as motive
power is its intense coldness which,
congealing the moisture in the sur
rounding atmosphere, quickly coats
with clogging masses of ice any en-
gine using it.
Aside from its possibilities as
power factor, liquid air has many ex-
tremely interesting physical chasrcter-
lstics, some of which cause one to
wonder if in this strangely cold fluid
the two extremes OF temperature do
not meet, at last forming q completed
circle, for it is noteworthy that drop
of this liquid, touching ones flesh, pro-
duces painful water blister and all
the conditions of inflammation that
would result from similar contact with
molten metal.
In this connection q brief descrip-
tion of q few of the more striking
physical peculiarities of this liquid
would not be amiss, tho the expert
ments by which these properties are
demonstrated being interesting chiefly
because of their spectacularity, the
in mere words impressions really de-
manding practical illustration.
For example, spirally coiled piece
of strip solder, upon removal after
momentary bath in the liquid, shows
all the lively resiliency of finely tenn
pered steel spring, while a watch
spring similarly treated becomes so
brittle as to crulnble to dust almost at
touch. A tea kettle containing
some liquid air, if held IN midair
at arms length, merely SINNERS away
much as would any well conditioned
kettle if over lively fire-but place
the kettle upon cake of ice, thereby
removing part of the layer of cold
air with which it had previously in
, sulated itself, and your kettle instantly
gives every evidence of an immediate
+ explosion, while to pour water into
the angry vessel only adds "fuel to the
. fiames," notwithstanding theN fact
that the water is instantly changed to
i tair.
D A most remarkable experiment is
f made by fastening lighted match to
:. one end of thin strip of carbon steel
8 steel containing a large percentage
! of carbon-then plunging it into a
s tumbler containing liquid air. The
carbon in the steel combines with the
q infammsble gas in the liquid to produce
: perfect combustion, and tho the
: match is quickly consumed, the steel
. continues burningas long as it is kept
!. immersed rather the carbon in the
!, steel burns, the under metal itself be-
: ing melted and falling in red-hot
|. :. globules to the bottom of the tumbler
But in even this experiment the ,ex
: tremes of temperature have not ye'
i. met.
d At the tip Of a carbon pencil heatec
t, to the point of incsndescence, as in al
q ordinary arc lamp, is said to exist th'
b highest known temperature -abou
q three thousand degrees Fahrenheit
l. piece Of this carbon may be heatet
it only to q dull cherry glow by holding
Z, for some time inlthe jet from "Bun
le sen burner" tho It becomes too hot Il
Is handle without asbestos protectet
9. tongs. When dipped into the tum
E. bier, full Of liquid air, however, th
st duly glowing tips Of the carbon in
st stantly come to . brilliant incandes
re cence, showing that the maximum