Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1886-01-06
FOB THE SCIENTIST.

of cobalt the tenacity of copper is
greatly increased-even as much as
so to 100 per cent, according to M.
Guillemin. The alloys are all red.
THE continuous heating Of cast iron
for several days in vacuum with
out melting, is found by u.
Foruuignon to cause the metal 10
become malleable, with a uniformly
black surface, dotted with black grains
OF amorphous graphite.
In certain Austrian coal mines
work is suspended in dangerous places
during fall of the barometer, expert
ments still in progress having shown
that the quantity and intensity OF ex-
| plosive gases greatly increase as the
atmospheric pressure diminishes.
RECENT observations, according to
E. j. Miers, of the British Museum,
show that crabs do not reach great
depths in the ocean. The Challenger
expedition obtained few specimens
from points more than 400 fathoms
below the surface, and only q single
specimen was found at a depth of / 900
fathoms.
DURING eighteen ascents of lofty
mountains, from 5000 to 1900 feet
in height, M. Vernet has made num-
Der of physiological observations on
himself. He finds that the strong ex-
ertion, both in mounting and descend
ing, caused an average rise in bodily
temperature of about 80; a rise in the
pulse from about seventy-five to
eighty-three in minute; and increase
in respiration from about twenty-one
to twenty-five in q minute.
Snow varies greatly in weight, &C
cording to the condition of the atmos-
phere. When very dry and "feath-
cry" scarcely anything is lighter than
handful of snow. On an average it
is found that a cubic yard weighs
about 187 pounds, or about one
twelfth of the weight of an equal bulk
of water. Ice is lighter than water,
but in nothing like the same proper
ton; and certain quantity OF snow
would, on the average, weigh only
about one-eleventh Of the same vol
ume of ice. The reason of course lies
in the greater compactness oftheice.
DIR. @. KELLER, of Zurich, claims
that spiders perform an important
part in the preservation Of forests by
defending the trees against the depre-
dations of aphides and insects. He
has examined g. great many spiders,
both in their viscera and by feeding
them in captivity, and has found them
to be voracious destroyers OF these
pests; and he believes that the spiders
in a particular forest do more effective
work of this kind than all the insect
eating birds that inhabit it.. He has
verified his views by observations on
coniferous trees, few broad-leaved
trees, and apple trees. An important
feature of the spiders operations is
that they prefer dark spots, and there
fore work most in the places which
vermin most infest, but which are
likely to be passed by other destroy
ing agents.
THE Investigations made by the
Prussian Firedamp Commission to
ascertain the causes of explosions in
mines show among other things that
many explosions attributed to fire.
damp, or outbursts OF gas, are really
due to the fine coal dust in mines. 1t
appears that all kinds of dust are
capable of exploding violently when
ignited by such means as the electric
spark, and that the explosion extends
much further with coal dust than with
fredamp. The experiments relative
to this infammability of coal dust are
stated to have been devised as nearly
as possible in accordance with the con-
ditions prevailing in practice. and were
carried on at the Koenig mine, Neun-
kirchen, Sarrebruck. A gallery, or
drift, driven from the surface, was
chosen as the place for treating the
dust, means being also provided for
, keeping the particles in state OF vio-
lent agitation by currents of air. To
provoke ignition of the dust, the cleo
trio spark was made use Of, g. means
that is far from furnishing that volume
of flame found by the French expert
mentors to be necessary to explode
coal dust. The tests were many times
repeated, more than 200 times in al,
explosions occurring in every case.
PROF. LoUDoN's proposed system OF
time, on the decimal plan, provides
: that the present day of twenty-hours
be divided into ten divisions, so that
each hour would correspond to two
hours and twenty-four minutes; this
hour would be again divided into a
hundred divisions, called minutes ii
necessary, each minute on the new sys-
tenn thus corresponding to Ia min
utes; again, this new minute division
: to be sub-divided for accurate meas
urements into one hundred divisions,
: called seconds. The advantages arts
ing from such system, as enumerated,
are, the abolition of the so-called A.
M and P. M, as has already been &C
complished by the 24-hour system; all
the advantages derivable from the
adoption of any system based on the
scale of 1O-namely, the inconven-
fences arising from the continual use OF
vulgar fractions and the use OF SYM
bols for each unit in the ordinary at
fairs of life; and, finally, the fact that
the time in hours and minutes which
for all practical purposes is sufficient,
is indicated Immediately by the clock
this latter being considered spe,
cially important advantage, as, by
the present system. it ia AWAY essen