Wessington Springs herald. (Wessington Springs, Aurora County, Dakota [S.D.]) 1883-1891, 1886-09-03
STUDY AND WORKSHOP.

STUDY AND WORKSHOP.
HousEKEEpEns will be Interested in
The pleasing information winch the
american e4rchitect gives, that the
Southern pine seems to be the natural
habitation in this country OF the clme1
which is found in immense
numbers under the bark of old trees OF
that species. If the wood contains nat
ural clefts, the insects and their eggs
remain in these after saving, and are
often carried in that way in the seams
Of large timbers into buildings. The
appearance of the bedbug,
which is the more familiar name of the
cimex, may be thus accounted for.
The pyrometer, or instrument for
very high temperatures, is
and expensive apparatus.
Two Germans-Messrs. Heisch and
Folkard- have simpliied it by making
with platinum or porce-
lain bulbs which will record the tenn
perature of even white heat. The
reading is taken in precisely the same
way as at present, with an ordinary
but the result is obtain
ed by tho pressure of air inclosed in
the bulb, which is exposed to the heat.
This pressure acts directly on verti-
cal column of mercury. The bulb is
sealed, and the instrument
is unaffected by changes in the height
Of the barometer.
Mr.. ALFRED NOBEL, the inventor of
dynamite and blasting gelatine, has re-
Gently introduced what he terms gela-
tine dynamite, which combines and
gives effect to the qualities of the two
great explosives that go to form its
name. It has gone little farther than
the test case as yet; but accounts of its
use in mines, limestone and granite
luarries, tunnels, and collieries show
chat it has advantages that the intelli-
gent workman appreciates; that it does
The work of dynamite in places that
cannot be we'll ventilated, and that it
leaves so little. of an offensive smell
that miners can go in almost imme-
diately, feel no bad effects, and get on
with their work.
A CURIOUS and instructive experience
mas been had recently by one of the
leading steel mills in this country. A
lot of material for bridge, fresh from
the mill rolls, was rejected by the in
spector for the buyers, much to the
of the producers. After the
Inspector had left, the manufacturers
decided to make an independent in
vestigation, which resulted in showing
that the rejected material did not come
up specifications. Further research fol-
lowed, and developed the fact that for
given number of hours after the ma
rial had left the rolls its physical quail
ties gradually changed, reaching
period of rest only after a certain time
had elapsed.
A NOVEL use Of the stereoscope was
made in the detection of
bank note. A hundred
franc note was submitted to the ex-
perts of the Bank of France as issued
by band of forgers, but the execution
was SO perfect that no defect could be
discovered by the closest examination.
As last resource the suspected
note was placed side by side with the
genuine one in the objective of
the two images of which,
as we'll known, overlie each other and
form single picture. The result of
the experiment was that the loop in
a letter of the forged note did not ex-
actly cover that of the genuine one,
showing that they had not been print
ed from the same plate.
PROF. W1LBuR's report to the Gov
on American clays and their
use for construction purposes describes
a terra-cotta lumber viii h has recently
been added to the list of mineral build
ing materials. A kaolinite of good
quality is mixed with sawdust, worked
by machinery into slabs, and is then
burned, sawed, and dressed. It is in
this condition ready for market, and is
said to be indestructible by fire, water,
or gases. 1t is poor conductor, and
suffers but slight expansion or contrac-
ton with changes of temperature. Its
weight is put down as one-half that of
brick. It can be worked with edge
tools, bored, and sawed, and holds
nails as readily as timber. It is also
made into hollow tile and fire-proof
casing.
A CONDENSED opera glass or pris-
matte spy-glass consists of chromatic
prism which has convex surface and
thus serves as an objective glass, re-
ceiving the rays and rejecting them by
interior total reflection to second re-
version prism, and finally to the eye.
The surface of this prism is ground as
q convex lens, and serves as such.
These spy glasses are very short, and
some ten diameters, or 100
times the surface, while an ordinary
good glass of this kind magnifies no
more than four or five diameters. They
are also provided with hair micro
meter, in order to enable artillerists to
measure distances with them. The
focusing is done by On upward or
downward motion of the second rever-
sion prism.
A CONNECTION, which has long been
suspected. between cows milk and