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

was the solid rock foundation they re-
luired. Any form of coffer-damming
against the terrific weight of this
treacherous obstacle promised mot
only to be expensive, but well-nigh i'm
possible, and was abandoned in favor
of plan so simple it is strange it had
not before been employed. Large hy-
draulic pipes, their lower extremity
tightly capped, were driven thru the
bed of quicksand at frequent intervals
along the route of desired excavating,
and inside of each of these pipes was
placed much smaller one fitted with
valves capable of almost instantly dis
charging the contents of the small pipe
into the larger one. The air in the
large pipe was now exhausted, part of
it being compressed within the small
pipe, and when sufficient pressure was
obtained the valves opened, permitting
the compressed air to escape into the
large pipe greatly expanded, and pro-
portionly reduced in temperature; this
operation was repeated continuously,
always using the same air, the temper
ature of which, being constantly low
cred with each successive compression
and expansion, eventually becoming
so cold as to chill the surrounding
quicksand, preventing its free move
ment and so rendering the task of ex-
cavating, within that zone, as simple
as would have been the handling of
ordinary sand.
In the reduction of air to its liquid
form, use is made of an elaboration of
the application of the theory just de-
scribed, the operation being necessa-
rily, prolonged, for it must be
understood that this liquid is the pred
uct not of powerful compression alone
but is the result of many successive
compressions and expansions which
constantly lower the temperature of
the air being used, alternately causing
the precipitation of liquid Ia very
small quantity of liquid as compared
to the volume of air used, but liquid
nevertheless) trifle opalescent in
color, and slightly perceptible to the
organs of smell, throwing off, as it
evaporates, vaguely pungent odor
and fumes almost as delightfully."- ex.
hilarating as the bouquet of newly
opened rare old wine.
| From the foregoing it will be appre.
ciated that the subject Of this paper
could in no sense of the word be
termed "hot air. On the contrary, il
is unquestionably the coldest product
; known to science! So cold, in fact
, that its actual temperature can onl!
be guessed at, as even alcohol freezes
almost instantly upon contact with it
. estimates, based upon its power o.
/ contraction over soft metals like solder
| however, place the mean Temperature
of this liquid in the vicinity of 300 de
, grees below zero, a temperature whicl
the writer frankly confesses t.
: be quite beyond his limits o
> comprehension. A Minnesota winter
r with it's thirty or thirty-five degree
: below, representing about as inhospi
: table degree of frigidity as one care
3 to become intimate with.
We have noted that liquid air is tn
. result of mechanical force calling int
. action certain natural laws peculiar t.
gases, but unlike the solids and fluid
4 into which some gases are convertibl
? it is not permanent substance. L
other words, constantly acted upon b
1 the relative intense heat of its. SUI
8 roundings, this liquid is ever strue
: Cling to return to its original STATE
q and so lively are it's efforts in this d
r rection, that cupful Of it if upturne
q at height of only three or four fee
Q is completely evaporated before
l. single drop can reach the floor. Wit
Q such force striving for liberty
n force equal to the pressure Of hui
It dreds of atmospheres-it is evider
q that as a purely mechanical powe
v this liquid is veritable giant besid
10 which the puny efforts Of such agent
l. as steam sink almost to insignifcanc
l. And in this very fsct-the excessive
Q, ness of its strength-lies its creates
& weakness, for the fact that It will NJ
b brook confinement, allowing its stol