The Columbia herald. [volume] (Columbia, Tenn.) 1850-1873, 1872-09-20
sCIENCg AND INVENTION.

| A RAILWAY IMPROvEMENT.-Va
Gus cOntrivances have been devised
| for indicating in the cars the name Oi
the station ut which the train Is next
| to stop: but no one of them has been
generally adopted Something of the
kind is certainly needed, and in Eng
land a patent has been taken out by
which this information is given through
| indicators i'm each car, which are work
ed by compressed air contained in a
reservoir forward, in such a manner
| that the indication of particular
name may be reproduced simultane-
ously and invariably in every car OF
the train.
EFFECTS OF ELECTRICITY ON MILK.
1t is we'll known that, when the
| weather Is stiltry and muggy, especial
ly during a thtffider-stOr it Is almost
impossible to keep milk ffom sOuring.
Recent discoveries seem 10 indicate
that this effect il produced by the
negative electricity, which seems to
have strange power to produce dis
integration and decay, while the posi-
tive current has preservative quality.
A current of negative electricity will
wilt twig in few hotlrs, while the
positive will keep it green for weeks,
and milk can be kept sweet for three
weeks in the sultriest summer weather
by passing through it a current Of posi-
tive electricity. Here is hint for in
ventOrs.
TURNING MEN INTO FIsHEs.-A
French inveiitOr has patented an ap-
raratus for swimmers. For the hands
he has large membranOus fin, which
is held i'm its place by loops passing
over the fingers and strap around the
waist. The surfaces presented to the
water by these fins Is so large as to
add greatly to the effectiveness of the
strokes of the arm, but not so large as
to exhaust the muscular power. Their
effect is to reduce very much the effort
required to swim without them. But
the greatest ingenuity is displayed in
the form and fitness of the fins for the
legs. which are attached to the ankles,
and are so formed that they act upon
the water. both I'm the movement of
bringing the legs together and throw
iEg them back. They act SO finely in
threading water" as swimmers call 1t,
that one can really walk II not on the
water, at least in it. The difference
between swimming with this appara-
tus aid without it, is very much like
the difference between rowing boat
with the handle and blade of the oar.
The old swimmer has no trouble in
using the fins at the first trial and is
surprised to find with what ea-e he can
swim without exhaustion. He easily
swims twice as fast with the apparatus
as without it, aud he can sustain HIM
self for hours upon the water, or SWIM
miles with it.
NEW BUILDING MATERIAL.-An-
other manufactured building material,
called apaenite, is being successfully
used i'm England. This, an artificial
granite or marble, Is cOncreted in a
mould by the action of chloride of cal
cium or water glass, combined with a
body of spar or other material. 1t Is
said to harden quickly, and to attain
an ultimate CRUSHING t'enrth OF three
tons per SQUARE inch, equa'ing that OF
granite; exhibits erf ct la pm ss and
delic cy of nOuli &, les de- admit
ting an exq':i ute deg. G of aOlislI; and
is ais, lainel 10 h. uDafiect' Il by eX-
pOsuTe to the weather or 10y acuis, the
co of its production I've ng actually
less than that of sca.l oil , or nameled
slaie. One of The most reli ,blt build
ing materials, pro,i,lccd Icy ar ifical
m, ans, is now formed by mixing
broken granite, the refuse of granite
quarri 5, With hydrau ic cement, and
steep NJ the mass i'm silicat'' of soda
For rs p.riosr, the concr, tie masses
to he sill ciir'i are immersed in tank
of silicai.. f soda, in which are placed
pieces o. a peculiar variety OF silicious
stone, which possesses the property of
having its silica i'm such a state rs to
dissolve in cold caustic soda; the lime
of the concrete mass takes silica from
the silicate, and the soda set free re-
dissOlves silica from the stone, thus
making the process continuous. The
substance resulting from this opera
ton is a silicated concrete, or stone,
and it is manufactured on large scale
in London, where several large build
ings have been constructed entirely
from it. Its economy, as compared
with natural stone, is great advan-
tage.