The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1886-10-20
POPLAR SCIENCE.

The world uses forty thousand barrels
of petroleum per day. At this rate
America has enough on hand to supply
the demand for three years.
1t is stated that Mr.. F. Siemens, OF
Dresden, has at length succeeded in
casting glass in the same way as metal
is cast and obtaining an article corrc-
spending to cast metal. This cast glass
is hard, not dcarer in production than
cast iron, and has the advantage OF
transparency, so that all flaws can be
detected before it is applied to practical
use.
DR.. lawson, in the Rocky Mountains,
has discovered remarkable jurasso-
cretace3us fora. 1t is found in sand
stone, shales and conglomeratcs, with
seams of coal. The beds lie in t"oughs
of the paleozoic formations, and extend
for 1C0 miles north and south. The
plants are 'conifers, cycoda and ferns.
Some are identical with species from the
jurassic from Siberia and the lower Gre
taceous of Greenland.
In Germany, where it was invented,
the Pieler safety lamps for mines is now
commonly used, having displaced the
famous Davy in large numb:r of mines.
In Belgium it is largely used, and the
French are also adopting it. This lamp
is solely intended for testing purposes
in mines. 1t burns alcohol and reveals
the presence of fire damp when the lat
ter is present in any proportion greater
than one-fourth PER cent. In this extreme
sensitiveness les the value of the lamp
for miners.
The field for geographical exploration
is not yet exhausted even in Europe.
Schrader states that in the north of Spain
several ranges of mountains exist, some
reaching height of 10, 200 feet, which
have no place on any geographical map.
In the Aran Valley another discovery has
recently been made. Triangu!ation
showed gap untitled between two
chains of peaks which approached from
different sides, had been supposed to
form a single range, and further explora-
ton proved that the gap contained a
large and hitherto unknown lake.
At the last meeting of the American
Association for the Advancement of Sci
ence in Buffalo, Professor Il. S. Wood
ward, of Washington, read paper on
the rate of recession of Niagara Falls.
He said that the area of rock WON away
at Horseshoe Falls between the years
1912 and 1875 was is, 800 square feet,
equal to 4.25 acres; between 1S42 and
1886, $500 square feet, or 5.G2 acres
between 1874 and 1856, $4,000 square
feet, or 1874 acres. The main length OF
the contour of the falls is 2,30U feet.
The time required to recede one mile, if
the rate is "a feet per year, is 2, 200
years. The minimum values for the
yearly rate OF recession, i. c., average
rate along the whole contour, are: From
1912 to 1873, 2.44 feet; 1912 to 1886,
2.42; 1875 to 1886, 2.3S feet.
Dana finds that the average height OF
the land above sca-level is about ,00C
feet, and that this woull probably cover
the bottom of the sea to the depth OF
375 feet; so that, taking the average
depth at Is, 900 feet, it would take forty
times as much land as exists above sea-
level to fill the oceanic depressions. The
mean height of Europe has BEN stated
to be GO feet; Asia, 1,150; Europe and
Asia together, 100; North America,
74S; South America, 1882; all America,
$50; Africa, probably about 1,GOO feet,
and Australia, perhaps 500. So far as
now known, the extremes of level in the
land are 5000 feet above the level OF
the ocean, in Mount Everest of the Him.
alays, and 400 feet below it, at the Dead
Sea. Asia has also great depressed
Caspian area; Africa, in the Algerian
"chotts," sinks to 100 feet below sea-
level; while in America, Deaths Valley,
California, reaches from 100 to 200 feet
lower than the ocean surface.