The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1885-08-08
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
THE GROWTH OF COAL.


THE GROWTH OF COAL.
The most recent light on the unsettled question
of the precise manner in which coal was formed
is furnished by the researches of Mr.. Edward
Wethered, who has been convinced, by micro
scopical study of coal from English mines, that
the beds were not formed by forests, but that the
fossil trees SO familiar to bOtanists grew in them.
The coal itself-that is, the plants which ulti-
mately formed 1.-THE regards as having been of
aquatic habit growing in a manner similar to
modern boys, though of much larger extent.
GREAT PROJECT.
The director of the Paris Observatory remarks
that the heavens may be completely photographed
in 5000 sections similar to section of the Milky
Way shown in a chart presented to the French
Academy of Sciences. The whole work might be
done at six or eight well situated observatores in
five or six years. 1t is declared that such work,
containing the photographs of over 100000
stars down to the fourteenth or fifteenth magni-
tude, and bequeathing to future astronomers an
exact picture of the starry regions at the close of
the nineteenth century, would certainly be the
greatest astronomic undertaking ever carried out.
AN INTERESTING OPTICAL EFFECT.
new French experiment consists in placing
two similar black paper. fgures-two crosses, for
example-quite closely together, at about three
inches from the eyes. When so held before
sheet of white paper, three separate crosses will
be seen. The phenomenon-illustrat the prin-
II. =, L. &Io
ultaneous vision of the two eyes. If figures of
complementary colors-as red and green-are used
upon dark background, a white figure will ap-
pear in the middle.
THE DECAY OF BUILDING STONES.
The Investigations of Prof. 7. Eggle.ton have
shown that calcareous materials are most affected
by the acid gases and rain-water of cities at a
height of about ten feet above the ground, the eff
feet gradually decreasing upward, and entirely
disappearing above height of 100 feet Water
proofng seems to be the only remedy, a wash of
sulphur proving to be the only preservative of
value for hard stones, while saturation with lin
seed oil may be recommended in the case of all
porous stones.
MISCELLANEOUS.
The Greenwich Observatory in England calls
for large telescope. This most famous astronO-
micaI establishment in the world is behind many
observatories in the size of its instruments, its
largest refracting telescope having aperture of
only twelve and three-fourths inches.
Attention has lately been called to two races of
men that must soon become extinct. At the pres
ent rate Of decrease, the Maoris of New Zealand
now reduced to less than As, 900 from 1000 in
Capt. Cooks day-must have disappeared by the
year 1000. The Laplanders are estimated not to
exceed 10000 in number, and are gradually be-
coming fewer.
In freshly fallen hailstones in France, Bous-
singault has observed temperature of 1875 de-
grees-or 1875 degrees below freezing point
while that of the surrounding air was about AZ
degrees. Other observers have noticed tempera-
lures of 1926 and % degrees in hail.
new insect, reported to be more destructive
than the phyloxera, has appeared in great num-
bers in the vineyards of some parts of Roumania
and Bessarabia.
A mass of lead in an elevated furnace in Paris
was completely dissipated by stroke of lightning,
no trace of the metal being found afterward.
The Maluva tree of Central India Bassia lati-
fsia bears flowers which are now being exported
to Europe for their sugar, of which they contain
more than half their weight. The tree resembles
the oak, and single specimen sometimes bears
ton of flowers.
Fur made from feathers is a product of recent
years. In many respects it is equal or even SUI
- c. L. r;al ;u uSad for
the borders of ladies' cloaks, dresses, etc., and
even sealskin cloaks have been successfully imi-
tated with it.
supposed new species of bear has been dis
covered in Iterup, the largest and most inacces-
sible of the Kurile Islands. In general appear
ance the animal is said to resemble the American
grizzly.
An apparatus for showing under the microscope
the combustion of metals by the passage of the
electric spark through them has been exhibited
to the Royal Society of London. The apparatus
is very interesting one, most beautiful color eff
fects being yielded by the different metals in
burning. lo.t
The water-supply of many of the artesian wells
in the Algerian Sahara is reported to BIO gradually
mean reservoir is replenished very slowly.
Trial trips at Nice with the submarine boat of
the naturalist Tosel have indicated that the ves-
sell viii render valuable service to science. It
can penetrate to depth of about 500 feet, and
its powerful electric lamps make easy minute
inspection of the sea.
An association of pharmacists in Paris has been
discussing the old question of the influence of
plants in bedrooms upon the health of the occu-
pants. The conclusion is that the plants without
flowers being preferable to those in bloom.
The Milan Society of Hygiene has made the
singular suggestion that the soil of cholera il
fected districts may adhere to shoes, and give
rise to the disease in localities to which it is
thus conveyed.
In recent balloon ascent, Tissandier, the
French aeronaut, secured "a instantaneous photo
graphs of the country between Paris and Rheims.
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