The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1873-02-14
NUMBER 26.
SCIENTIFIC NOTES

Z
lessness by exterminating the forests.
Two thousand years ago, those lands
were celebrated for tI1eir wonderful
productiyeness, and were said to be the
most beautiful In the world. In 1900,
Humboldt visited Venezuela, South
America, and was informed by the na-
tives living IN the valley of Araguay
that they had noticed, with great aston
ishment that a lake which lay In the
middle of the valley has decreased in
volume every year; the cause of this is
clearly traced TO the telling of a great
number of trees which grow on the sur
rounding mountains. In Hungary the
periodical droughts are universally at
tributed To the humiliation of the
forests. In Cairo, Lower Egypt, great
many years ago, rain fell but seldom,
only once in three or four years but
since the time of Mohammed Ali,
twenty to thirty millions of trees have
been planted, and the result is now that
the people have from thirty TO forty
rainy days every year. Surely these
few of the many examples are warnings
| sufficient to put us on oar gaard.
SINGULAR CHANGES ~ IRoN.-PrOf
Mayer gives some interesting statements
the result of careful and prolonged
researches made by regarding the
effect of magnetism on iron. He states
that he has discovered by means of the
Saxton comparator, that rods of iron
suffer permanent elongatiUn by mag
netizatiOn of one hundred and fifty nail
honts of an inch. English refined
| iron gives the maximum of this elonga-
| ton, and scrap iron the minimum.
Whether the current is gradually in
| creased IN intensity, or whether it is
sent full charge at once, it produces the
! same degree of elongation. Prof
Mayer found, on his experiments, that
with one cell the elOngation took place
in six-tenths of a second with twenty
five cells it took place in two-tenths of |
a. second. 1t is thought that this !
elongation of iron under magnetism /
being fact, it might make, in its effect !
on the earth, an appreciable difference ]
in the length of the day This can be |
detected by the means which astronomy /
affords; even 50 infnitesimal change
in the day as that of seven-hundredtbs ]
of a second would be perfectly easy to |
discover now.
SOLAR PHENoNENA.-One of the most |
gaging the attention of astronomers is |
what are known as the solar prominen-
ces. Observations made with the largest /
telescopes declare these prominenees to i
be streams of intensely heated hydro
gen, which are elected from the sun /
with such velocity that they would |!
reach the earth in q few hours if of sufii-
cient volume. That there is enough /
hydrogen in the sun to produce such
volume is not at all doubtful, if only
the forces which leads TO the eruptions
should unite sufficiently at one time.
Moveover, such a thing is not without
precedent In May, 1858, the star I,
of the constellation Corona Borealis,
which had not been visible to the nnas-
sisted eye, suddenly frightened mp to a
star of the second magnitude. An ex-
animation showed that it had become
enveloped IN a vast atmosphere of heat
ed hydrogen, which extended from it as
far as from the sun 10 the earth, and
subsided In about three days. 1t is
argued, therefore, that our sun is es-
sentially of the nature of that star, and
that such.an event is as possible there
as it was in the other case.
IMPROVED INDIA RUBBER TUBrSs. -
1t is well known that ordinary vulcan
lied india-rubber tubing becomes satu-
rated with gas, which again evapOrates
at it's outer surface, causing a most
offensive odor. An invention for pre- |
venting thus, by coating the india-rub-
Der with varnish, has lately been
brought forward III England. The
principal feature III this method is, that
the varnish is easily made, and it rem
ders the substance Of the tube imper-
vious 10 gases The varnish is COM
posed of linseed oil and fine litharge,
or white lead, IN the proportion Of one
quart Of oil to one of litharge These
substances are well boiled together un-
til brought to a proper thickness or
body, and, while hot, the composition
is applied by running it through the
tube TO be coated or lined. The var
nish for the outside Is made sy mixing
one quart of linseed oil with q half |
pound of litharge and adding to the
same about gill of gold size. These
ingredients are we'll boiled together,
and, while hot, are applied with brush
or sponge.
A STRANGE phenomena has, 1T seems,
been discovered 10y the British survey
ing ship Shearvater, which vessel, hav-
ing accomplished her task for this
season. has lately returned to GalliPOh
The labors of the surveying parties on
board have, says the Dardanelles cor
respondent of the Leyant Herald,
been crowned with satisfactory results,
and one highly interesting fact has been
ascertained Of which the existence was
never before sur1nised. It was found |
that the proverbially rapid current
which runs from north TO south both IN
the DadanelIes and the Bosphorus Is
only superficial, for at the depth Of 20
fathoms the surE eying party discovered,
ia the course of their soundings, that
there exists an under current running
with prodigious force into the
Black Sea. So test the strength Of this
under current special apparatus was
constructed and attached to tho ships