Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1875-08-26
MECHANICAL AND SCIENTIFIC.

The somewhat novel theory has re-
Gently been advanced by NJ. Meunier that
the planet Mars is much older than the
earth, because of the ratification of its at
mospheres and the small extent of its seas
The form of the latter according to M.
Meunier, is exactly that which the terres-
trial oceans would assume after partial alb
sorption by the earth's crust If, for exam
pie, the Atlantic Ocean were absorbed so
that only that portion included in the con-
tour made by the uniform depth of 10000
feet were left, the shape would be in all
respects similar to that of some OF the seas
recognized in Mars. NJ Meunier's theory
will hardly be accepted, we think in astro-
nomical circles.-N. 7. Sun
M. Schering states that glycerine may
be burned in any lamp so long as the
flame is kept on'a level with the liquid.
The latter, on account OF its consistence
will not ascend an elevated wick. AS the
flame, like that of alcohol, is almost color
less, and as the material is especially
adapted for absorbing a large proportion
of saline substances, nj. Schering has re-
Gently made experiments in coloring the
fame with various bodies and with salts
factory results BY introducing substances
rich in carbon it appears that the flame
may be rendered suitable for Illuminating
purposes. The low price of glycerine and
its property of not volatilizing at high tenn
peratures add to its advantages in this ai-
rection
The union of Europe and Africa, by
means of a tunnel under the Straits of
Gibraltar, is one of the great engineering
schemes at present contemplated. This
tunnel, as projected, is to be a right line,
extending between Tarifa and Algesiras,
on the Spanish coast, to Ceuta and Tangier,
on the Morocco shore, the submarine por-
ton to be A, 100 feet in length, or nearly
nine miles. This vast enterprise offers, it
is said, more difficulties than the similar
work under the English Channel, although
the latter will have more than twice the
length. The maximum depth of the chan
mel at the point to be traversed is stated to
be only 1863 feet, while that of the Straits
is 1851 feet. Surprising the tunnel UNI
der Gibraltar to be bored at distance
of /, 900 feet under the bed, its total depth
under the sea level would be over 5000,
while the entry and exit galleries would
be each three miles in length.
"A method of coating iron with copper
so as to protect the former from the action
of sea water and the like is described in
the Deutsche Ilust. Zeitung. The iron, it APP
pears, is first cleaned and rendered per-
fectly bright by means of acid and then
immersed in a bath of melted copper,
which is maintained at a very high tenn
perature, so that it not only covers the
iron but becomes incorporated with it,
Iron coppered in this way can, it is said,
be hammered and rolled without the cop
per tearing or peeling off, and specimens
left in contact with sea water for period
of nine months have been found unat
tackled and capable of being hammered
and rolled out like new metal. Iron
plates covered with copper in this way
are claimed to possess two important adj
vantages over pure copper plates, namely:
they cost less and are harder and stronger.
There is also a great advantage in using
coppered iron wire for telegraph lines in
stead of galvanized iron.