Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1894-08-15
SCIENCE AND INVENTION.

There is no article of food in which
dangerous microbes exist and thrive to
such an alarming extent as in milk. The
moment warmth is impaired to it incu-
baton takes place-the microbes begin to
terminate. 1t is not at this stage that
the danger exists, but after a certain
period when acidity follows: All milk
should be sterilized, either by boiling or
by the Pasteur method, but even then
there is no guarantee of safety. Every
housekeeper should have a supply Of
litmus paper on hand. The least acidity
will be detected by the paper.
DIR. Joule's studies in mechanical
equivalent of heat brought forth the
compound engine. In 1850 it required
IA 800 pounds of coal to transport ton
of grain to Europe Now $50 pounds will
carry a ton. An inch cube of coal will
carry a ton of cargo two miles. In 1880
the cost of carrying q bushel of grain
from New York to Liverpool was Is
cents; in 1856 it cost 2 cents.
A cheap and simple method of testing
iron and steel is to use nitric acid. A
drop placed on iron leaves a gray stain.
The softest iron makes the lightest stain,
and the best steel the blacklist. The diff
ferent grades of iron and steel can be de
termined by the various shades produced
by the acid
Natural gas is gradually declining in
pressure throughout the country. From a
pressure of 210 pounds in 1887, it is now
reduced to less than half that amount.
The banner year was 1888, when the
100000. Last year the product
was worth less than $15,000,000 In
diana was the leading state. Her prod
uct alone being valued at S5,71S,000,
and it was the only state showing an i'll
crease for 1898.
Since the removal of garbage is an
important subject at this time, attention
might well be called to the systems in
use in st. Louis, Cincinnati and New Or
leans. In st. Louis especially, the plan
of converting it into fertilizer is a sue
cess. The garbage is put into Il steam
jacketed cylinder, surrounded by steam,
and about so per cent. of the water evap-
grated. Naphtha is then added and al
! lowed to remain forty hours, to dissolve
the fat and oils, and the naphtha is after
| ward washed out The residue is then
dried and makes a fine fertilizer, which
contains all the alkali and phosphates of
the garbage.
Potatoes can be preserved for an in
definite time by radically destroying the
shoots. These can be cut out with the
point of a knife They are then inn
luton of sulphuric acid and taken out
and dried. The solution affects only the
skin of the potato, and does not deterior-
ate it, as the sulphur is driven off by the
neat.
j. w. Swan exhibited before the Roy
al society a specimen of gold leaf .000004-
inch thick. He made it by electro-plating
a thin film of gold on a thin sheet of cop
per, and then dissolving the copper with
perchlorde of iron. This is only one
tenth the thickness Of the finest film ever
hammered or rolled.
What is called a japanese novelty is
plain mirror upon which no figure or
design is apparent, but which distinctly
shows a figure or pattern when a reflection
of the mirror is thrown on a screen. The
secret lies in etching the figure on the
surface of the mirror and it is then pol
ished until the pattern is no longer visi-
ble 1t will still show when the ray of
sunlight is reflected on a screen.
A car travelling at the rate of twelve
miles per hour goes twenty-five feet per
second. A motorman with one hand on
the rheostat and the other on the brake
cannot possibly apply the brake block
on the wheel within three seconds. That
means siXty-siX feet before the car be-
gins to feel the impulse of the brake
Talk about accidents on the trolley lines!