Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1882-02-15


precisely as though it was pure.
A GOOD vARNIsH.
A light, glossy varnish, for labels,
maps, etc., is made out of th1rty-twO
parts of collodion and one part of castor
oil. It is durable and waterproof. A
good varnish- brush must be employed,
and the varnish must be applied with
decided, steady, regular strokes. The
work should be placed In sloping posi-
ton during the application of the var
nish, and should be kept nearly upright
until dry.
OPTICAL DELCSIONS.
1t is well known that black object
on a white ground Will appear to be
much larger than it really is. A white
stripe, for instance, on a black surface,
although both be of the same width.
This phenomenon of simultaneous con-
trast is physiologically explained by
Pater Scherffer in this way: When one
of our senses receives double sensation,
one of which is active and strong while
the other is weak, it will be found that
the latter is not felt. This must be par
ticularly the case when both impressions
are of the same kind, or when the strong
effect from an object on one of the
senses is followed by another of the same
kind which is milder and weaker.
PHOTOGRAPHY BY ELECTRICITY.
The method of photographing with
the electric light adopted, with marked
success by nj. Liebert, in the Rue de
Londres, Paris, is described in a recent
number of La Nature. A hollow hemi-
sphire about two metres in diameter is
suspended adjustably from the roof sc as
to present its cavity toward the person
to be photographed. In this cavity there
are two carbons, one fixed the other
movable by means OF screw. The lat
ter can be brought toward the former at
right angle. There is 10 other mechan-
ism; the time of exposure is so short
that the light does not fail in it. The
novelty of the system consists in not
throwing the light directly on the per-
son; the beams In that direction are
thrown back from a small rejecting
screen to the concave surface of the
hemisphere, which is painted white.
The individual is thus flooded with well
dispersed light, which the eyes bear
without fatigue. The apparatus is
placed somewhat laterally, and with the
convex side toward the camera.
GLIDING ON GLASS.
A correspondent gives these directions
in The English Mechanic for gliding:
Designs or ornaments of any kind can
be produced on glass Or ivory, by paint
ing, with very fine camel-hair pencil,
nitro-mutriate of gold over the designs.
Hold the glass or ivory thus painted
over bottle, in which hydrogen is be-
ing generated; in a short time the design
will shine with considerable brilliancy,
and viii not tarnish upon exposure to
the air. The thickness of the coating
of gold is not more than the ten-millionit
part of an inch. Another method, in
which the use of hydrogen is dispensed
with, is to mix gold powder with borax
and water; then paint the lines and orna-
ments with it. When quite dry, the
glass is to be put into a stove, heated. to
high temperature. The borax is vitri-
fed and cements the gold with great
frmness to the glass. To make gold
powder, put into an earthenware mortar
some gold leaf, with a little honey or
thick gum-water. and grind the mixture
till the gold is reduced to extremely mi
mute particles; when this is done, little
warm water will wash out the honey or
gum, leaving the gold behind in powder
COMPRISING FLUID STEEL.
A useful method for the compression of
fluid steel, invented by 81. r. Jones. of
Pittsburg, Pa, was described by Mr.
Davis at the late meeting of the Iron
and Steel institute, held at Liverpool,
England. The process consists in sim
ply admitting steam at high pressure
to the tor of the ingot mold, immedi-
ately after the metal has been poured.
A steam receiver, for the sake of con-
venience, is fixed to the side of the
ingot crucible. This receiver has a
number of cocks, corresponding with
the number of molds. India rubber
pipes are provided to conduct the steam,
one end being permanently fixed to the
receiver, and the other, by means of a
coupling, attached to the lid of the
mold. In practice a higher pressure
than from eighty to one hundred and
fifty pounds has not appeared to be
necessary, and the higher pressure is
used In the case of mid steels. Under
tins process the ingots are turned out
free from porosity and with perfectly
level top. The steam, besides consol-
idating the ingot, acting on the end,
cools the top of the ingot and allows it
to be conveyed to tie reheating furnace
sooner than when the old process was
used.
LAMPS THAT RIDE THE SEA.
The illuminated buoy is wonderful
invention. Imagine an enormous lamp
riding the waves. The buoy is COM
pact wrought-iron vessel, which serves
as a receiver of compressed gas. The
duration of the fame depends upon the
size of the buoy. Some ia use in Eu-