The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1889-07-04
SCIENCE AND INDUSTRY.


A new process Of hardening
plaster of Paris has been discovered
whereby it can be adapted to the con-
struction of flooring in place of wood.
Photographs of the fight and ex-
piosion of dynamite cartridges are
among the achievements of the instan-
taneous method of photography. How
our grandfathers would have wondered
at such pictures!
The military engineers of Austria
are experimenting with aluminuma
bronze with view to adopting it for
gun-barrels, for which it offers the
great advantage of not rusting when
exposed to wet.
The great Improvements in the
construction of apparatus, and the ap.
plication of the microscope to lithol-
ogy, have resulted in successful at
tempts at the reproduction of all the
modern volcanic rocks.
-Southbridge, Mass, has the largest
spectacle factory in the world. More
than three-fourths of the gold specta-
cles and eyeglasses made in this coun-
try are made in Southbridge, one COM
pany alone in that town having turned
out 1, 100000 pairs last year.
Over million pianos have been
constructed in and 100000 imported
into the United States. since 1880. So
some careful observer informs us. elm
vention" tells us that the American
pianoforte manufactures now turn out
$4,000 instruments every year.
The Chicago Sanitary News says
that the board Of health of one of the
Eastern States, in a late report, gives
an account of a well OF water contain-
ing 1872 grains of solids per gallon.
yet the pollution could not be recog-
nized by the senses. and several per-
sons lost their lives by its use before
the cause was discovered.
An interesting fact is that one Of
the greatest problems now perplexing
scientific men-the production of heat
less light-has been already solved by
nature. The light from a luminous
beetle-su sufficient for reading a news
paper-is shown by the spectroseope
to be all of one kind, and just the kind
for seeing, while the thermopile finds
no evidence Of heat. Yet in all our
artificial lights vast quantities Of fuel
are wasted for useless heat.
The lightness of snowflakes is the
results of their surface being so great
when compared with their volume,
and is accounted for in some degree by
the large quantity of air amid their
frozen particles. Snowaakes contain
about nine times as many volumes of
air, entangled, so to speak, among
their crystals as they contain water.
Very fine and lightly deposited snow
occupies about twenty~four times as
much space as water, and is from
ten to twelve times lighter than an
equal bulk of that fluid.
R. L. Weatherby, the manager of
the ocean cable companies repairing
service, has discovered that the cause
OF the rapid impairment of ocean cables
is found in the iron used to enwrap the
cores of the cables. The action of
deep sea water on iron tends to soften
itand destroy its cohesiveness, whereas
hemp will remain at any depth in the
sea for scores of years without being
injured. Hence, if the cable cores
were wound and covered exclusively
with hemp. instead of with hemp and
iron as they now are, their destructi-
bleness would be very greatly lessened.
The average life of a cable, as at pres
ent constructed, is only twelve years.
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