Worcester morning daily spy. (Worcester, Mass.) 1888-1898, 1898-03-20

out any serious effect, if they be with
drawn promptly. The fingers come out
dry not wet, and during the momen-
tary immersion only a sensation Of cool
ness is felt. A thin wall of vapor which
is instantly formed about the fingers
protects them for a second, or frac-
ton of a second. But let them stay
there for a longer period, and they
would be seriously burned. In like man
ner few drops may be poured out in
to the palm of the hand without harm
if shaken off to the floor almost imme-
diately. While lying in the hollow of the
hand the liquid shows tendency to
gather itself up into spherical shapes
and to separate itself into distinct
globules.
| Apply a warm hand to the exterior of
/ the globe or to a thin tumbler contain
ing liquid air and the contents will boil
more vigorously and emit this vapor
! more profusely. A single finger inserted
into the open mouth of the globe, but
without touching the surface Of the
liquid will hasten the VaporiZing
| process, so that the digit itself appears
to give off steam. When boiling the,
liquid air is as white and opaque as
milk owing to the large number of
small bubbles developed therein. Pour
| ing water into a dish containing liquid
air results in the conversion of the
| former element into ice, although the
latter fluid is boiling vigorously in con-
sequence. A chunk of this ice, too, will
produce ebulltion. Or if a tumbler con-
| tanning liquid air be partially inn
mersed in a basin of cold water, the
| latter will produce the same effect.
| Here is one of Mr.. Triplers prettiest
| demonstrations A thin, straight-sided
glass lumber is half filled with liquid
air and then set into basin of water
two and one-half or three inches deep.
| So intense is the cold produced by the
| evaporation of the air that a film of ice
| is quickly formed on the outside of the
lumber When this she'll has acquired
a thickness of an eighth of an inch, it
may be detached from the tumbler, now
| once more empty, by pouring into the
glass a little water. Thereafter the ice
| film is manipulated with cotton hand
kerchief. Holding the shell in one hand,
! Mr.. Tripler pours into it with the other
| half an inch or an inch of liquid oxygen.
A burning match at the end of a foot
or two of steel wire or ribbon, is now
| dipped into the fluid, Instantly the end
! of the wire begins to burn, scintillating
| beautifully. Sparks fly in all directions
for a distance of foot or two.
"There you have a very fine. tenn
perature contrast" says Mr.. Tripler.
! THE burning steel represents about
| 1000 degrees above zero The ice cup
! and oxygen mean 300 or more below =
For another pleasing experiment Mr.
J Tripler took a globular glass vessel, 10
! or IL inches in diameter and looking
/ like a huge carafe, except that its walls
| were smooth and thin. Tt was nearly
| full of water. Into the open mouth was
| poured a tumblerful of liquid air. This
| being a trifle lighter than the water
| f1oated in layer which at first was an
| inch or more in thickness, The down
ward impulse acquired from the act Of
pouring it in caused little oscillation
of level for a moment or two
Then, after short interval, large
gIobules of it's lighter fluid would show
disposition to dive to greater depth,
but always returning to the surface
| again The dancing of these spheres,
seen from the side, was fascinating
spectacle. The air remained distinct
| from the water, and did not mix as one
might expect. So nearly the same was
i the specific gravity of the two, that only
the most trifling change was necessary
i to alter the balance. ( And every now
i and then the plunges of the upper ele-
J ment would go deeper than before, until
| finally, for a second, the bottom of the
vessel was touched. The little masses
of liquid air looked like glass alleys or
/ Jackson balls, nearly an inch in dame
| ter, but -colorless. They glittered like
] jewels. The increasing density of the
/ air, IN consequence OIL psIIldl eNdpOFd-
ton, as shown by this experiment, was
attributed by one of the bystanders to
| the carbonic acid gas in the atmos-
| phere.
| A copper tube having a thickness of
nearly a quarter of an inch, diameter
of an inch and half or two inches, and
1 a length of ten inches, and open only
| at one end, was fastened upright in a
wise. A tablespoonful of the liquid air
| was poured in. a wooden plug was
| quickly driven into the mouth with a
| hammer, and then the company was
| warned to step off to a safe distance.
A moment later there was an explosion
| like that OF small cannon, and the plug
| snote the ceiling violently. The
warmth of the metal had yaporized the
liquid, and a great pressure was thus
| developed
| Mercury poured into a mould was fro
zen into a solid block three Inches long,
| an inch or more thick and an inch wide
| The threaded ends of two screw eyes
were laid in place at the outset so that