The Forest Republican. [volume] (Tionesta, Pa.) 1869-1952, 1886-09-01
sCIENTIFIo ANp TNpusTRlAL

In new French method of diagnosis
the condition of the eye is accurately es-
timated by means of variations in sounds
seat through q sensitive form of tele-
phone placed against the eyeball.
The river Euyhrates is reported to be
gradually disappearing in the spreading
marshes just below Babylon, which have
ruined the steamboat channel and are
now obliterating navigation for row.
boats.
In an address at the London Royal In
stitution Mr.. William Anderson has
offered the suggestion that cork, on ac-
count of its porosity, may prove to be
superior to India rubber as material for
waterproof overcoats.
The average hight of Europe has been
estimated by a German geographer to be
974 feet. Switzerland shows the greatest
mean hight, 4, 624 feet; and the Neither
lands the least, thirty-one feet. Inter
mediate are Spain and Portugal, 2, 29S;
Austria 1859; Italy, 1895; France,
1899; British Islands, ia; Germany,
COL; Russia, sos; Denmark, 115.
There has been of late so much alarm
ist talk about; the exhaustion of our
coal fields, says the London Truth, that
it is good news to learn that an inventor,
Mr.. II. M. Marchant, has at last per-
fected an engine in which the steam is
returned to the boiler and, so to say,
used over and over again. The saving
in coal thus to be affected is calculated
at eighty per cent. Besides saving coal,
however, this invention will upset q pet
theory of the engineering fraternity, who
have always considered this problem as
impossible as perpetual motion.
An interesting experiment, showing
the influence of electricity on the growth
of roots, has been made in Germany by
Prof. Hodefeiss. Plates of copper were
thrust upright into the earth and con-
nected by wires with similarly placed zinc
plates about 100 feet distant, an electric
battery being thus formed, with the earth
between the copper and zinc in the cir
cult Both potatoes and beets planted
between such plates gave an increased
yield-beets fifteen per cent, potatoes
twenty-five per cent-as compared with
other parts of the same field.
Up to the present all mirrors manufac-
tured in the United States have been
from imported glass. The quality of
the glass to retain the silvering and give
perfect production of the object must
be of the best. This quality Pittsburg
had never been able to produce until
natural gas came into use. Now, by its
aid, the fineness of the glass produced
rivals that of the imported article. The
entire absence of impurity, the perfect
fusing of the ingredients, the rapidity of
the melting, and the pure, intense flame
for reheating or working, are the princi-
pal advantages.
According to the calculations made by
a scientific writer lately, it requires pro-
digious amount of vegetable matter to
torn a layer of coal, the estimate being
that it would really take a million years
to form coal bed 100 feet thick. The
United States has an area of between
300, 900 and 400, 900 square miles of coal
fields, 100, 900, 900 tons of coal being
mined from these fields in one year, or
enough to run ring around the earth at
the equator 81 feet wide and 81 feet thick,
the quantity being sufficient to supply
the whole world for period of !, 500 to
1900 years.
Proctor remarks that common error
is the supposition that the earth moves
in an obviously elliptical path, whereas
it really appears to travel in circle.
Taking theearth's orbit when its eccen-
tricity was very nearly at its greatest,
$50, 900 years ago, the numbers 325 and
324 represent the actual proportion be-
tween the greatest and shortest axes of
the figure described by our planets mo-
tion around the SUM- so that, if circle
is drawn with radius Of three and a
quarter inches, it nowhere departs more
than the hundredth part of an inch from
the ellipse which would represent with
perfect accuracy the orbit of the earth
$50, 900 years ago, when it was SO much
more divergent from an exactly circular
form than now.
oI