Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1882-05-31
CURIOUS, USEFUL AND SCIENTIFIC.
NICE CALCULATIONS.

LII GD0 BC1OuCluC SuuuCIy OApOAhAASh0S
at Woolwich the flight of shot was
measured to within the milliontb part OF
second.
WISE PROBATION.
In Berlin it is customary to have an
analysis made of the air IN the cellar be-
fore hiring house. One can then form
some notion of whether the house is
healthy or not.
MAKING ICE.
Some interesting and successful ex-
periments have been made recently at
the laboratory of the International Ice
Machine Company, at Green Point, N.
Z, on a new method of making ice.
This is called the "low-pressure binary
SYSTEM" and it's novel feature is the
liquefaction of the ammonia employed at
low pressure by glycerine. The system
is called binary" because two liquids
are employed instead of one.
ARTIFICIAL LIGHT.
A Harvard professor has been expert
menting to determine If the yellow color
of artificial gas and lamp light is injuri-
GUS to the eyes of those who work by
such lights. He has concluded that all
radiated from the flame and that reflect
ed from the printed page. He looks for
ward to the perfection of theincandescent
carbon electric light as a remedy for
the most widespread evil that afiicts
the human vision.
WATER MOTORS.
The City of Geneva, Switzerland, fur
nishes water for small engines at about
cent cubic yard, under pressure of
Al atmospheres, thus giving a horse
power for seven cents an hour. This is
only half the charge that is made for
water for domestic purposes. Two
kinds of apparatus are used for motors,
one acting on he plan of the turbine and
the other through pistons which are &C
tuated by pressure. The second seems
to be the more generally preferred.
POIsoNs.
It may now be said as the direct con-
illusions of science that no poison can be
given which will not leave an inevitable
proof in the very body of the victim, and
the latter thus becomes the most danger
Gus with men In the case. Arsenic, for
instance, is readily identified, as may be
learned from the Malley trial. Strych-
nine reveals itself in the rigor mortis, Gas
it is termed) or rigidity of the corpse.
Prussic acid tells its tale In the condition
of the blood, and hence there can be no
concealment in such cases. The capital
convictions in this country include cases
of strychnine, arsenic and aconite, and
between that both laurel water (Which is
of the same nature with prussic acid) also
IL
COPYING ENGRAvINGs.
To copy engravings in ink from paper
or glass, the Scientific American gives
these directions: Flow the glass plate
with good photographers negative var
nish thinned down somewhat, and when
this has partly dried ESQ that the varnish
will not run into the paper lay the
smoothly printed side down upon the
vanished surface, and put it under
slight uniformly apportioned pressure
for twenty-four hours. Then moisten
the back of the paper, and by means of
piece of soft rubber rub off the
softened paper. If this is done with
care the linked lines will remain attached
to the vanished glass surface. AS the
thin varnish is quite transparent, this
is equivalent to transferring the engrav-
ing to the glass surface. The transfer
is frequently improved in appearance by
giving the plate (and transfer) a second
coat of the varnish For lantern pur-
poses it is better to cover the surface
bearing the transfer with a second plate
of glass, and bind the edges with thin
cloth or stout paper.
HEATING BY SUNSHINE.
Prof. E. S. Morse, of the Essex Insti-
tute, has devised an ingenious arrange
ment for utilizing the heat in the suns
rays In warming our houses. His inven-
ton consists of O surface of blackened
slate under the glass fixed to the sunny
side or sides of house, with vents in
the walls so arranged that the cold air of
the room is let out at the bottom of the
slate and forced in again at the top by
the ascending heating column between
the slate and the glass. The outdoor
air can be admitted also, if desirable.
The thing is so simple and apparently
self evident, that one only wonder is that
it has not always benin use. It's entire
practicalness is demonstrated in the heat
ing of the professors study in his cot
tage at Salem. The value of the i'm
provement for daily warming buildings
like churches and schoolhouses, which,
when allowed to get cold between using,
consume immense quantities of heat be-
fore they are fairly warmed again is evil
dent. Of course some other means of
heating must be available when the sun
does not shine. But in the colder re-
gions, say in the northwest, the sun
shines greater part of the time and
hence the saving of artificial heat would
be very large if the sun heat could be
turned on - for s OF 10 hours out OF
the a. Scientific american.
ENGRAVING BY PHOTOGRAPHY.
How many of the illustrations which
are printed in books, magazines and
newspapers are executed entirely through
the aid of photography probably very few
persons are aware. The process which
during the last few years has become of
SO great an Importance is called photo
engraving; of the methods there are
many, differing in minor details, and OF
more or less value. The most simple