The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1885-11-04
POPULAR SCIENCE.

The seed vessels of the bird-catching
tree of New Zealand secretez avery
sticky gum, in which notmerely insects
but birds are entangled and perish.
In Southern Russia vineyards are freed
from p%hylloxera by planting hemp near!
the infected vines. The parasites. are
attracted to the hemp by its strong odor,
and the roots prove to be poisonous to
them. ~
Professor A. Landmark, chief director
of the Norwegian fisheries, finds that
under favorable conditions a salmon may
sometimes jump sixteen feet ~perpendicu-
larly, and that when the fsh's leap isa
foot or two short of the height Of the
waterfall it often succeeds in completing
the ascent by a dextrous use. of the tail
The strongest wood in the United
States, according to Professor Sargent,
is that of the nutmeg hickory of the
Arkansas region, and the weakest the
West Indian birch. The most elastic Ia
the tamarack, the white or shellbark
hickory standing far below it. The least
elastic and the lowest in specific gravity
is the wood Of the Ficus anrea. The
highest specific gravity, upon. which in
general depends value as fuel,is attained
by the b.uewood of Texas.
Water does not boil until the tension
Of tho vapor formed by heating it lis
greater than the atmosphere's pressure.
At the sea level, where the pressure Of
the atmosphere is about fifteen pounds
per square inch, the water must be heated
to 212 degrees before its vapor has sufaci.
emit tension to overcome this pressure.
At Argenta, Montana, where it is SO
much above the sea, having a much less
depth of atmosphere, the pressure is not
so many pounds and the boiling point is
correspondingly lower. Water boils at
about 200 degrees there.
The dunes of Gascony, according to q,
recent report by the inspector of French
public works, cover a surface Of more
than 200, 900 acres, and are more than
$50 feethigh and three or four miles wide.
The fine sand composing them was
formerly pushed constantly inland by the
wind, covering fields and villages, and
even burying churchesup TO their towers.
Since. 1850 the difficult task of fixing the
sand hills by creating q growth of yege.
tation. on them has been in progress, and
has at lengthresuIted in ayerting q great
public danger and forming o fine forest
The formation of new. dunes is prevented
by the building of wooden palisade,
against which the sea raises so steepae
bank that no sand can be blown oyer the
incline. RI
4 chemical examination Of water
brought up from great depths in the
Mediterranean proves, as suspected, that
the deep sea water is more salt: than that
at the surface, though nothing can be-
found to show the existence Of bed OF
salt, at the bottom to produce such extra
saturation; in fact strata of water Of less
density are met with below those OF,
greater density. Thus it appears that
the outer. current in large part carries
with it the excess of salt productivity the
surface evaporation, the cause of thetcir-.
culation being due, it is believed, to hy-
drostatic action purely. That is, the
water of the Mediterranean is continu-
ally losing b yevaporation a larger amount
than is returned to it by rams or rivers
and, consequently, the inflow from the
Atlantic must take place to keep up this
level. If this inflow consisted Of fresh
water the total quantity of salt in the
Mediterranean would remain the same,t
and the density, therefore, wouldundergo
no increase; but, as the upper currentof
salt water brings in a certain quantity OF,
salt in addition to that which the Medi,
~terranean basin previously contained,
the density of this water is increased, and
a column of it reaching to any given
depth becoms heavier than q corresponds
ing column of Atlantic water, the excess
of downward pressure consequently dis
placing the lower portion of the column
Of water, which will flow outward as an
under current.