The Wonder Book of Knowledge: The Marvels of Modern Industry and Invention, the Interesting Stories of Common Things, the Mysterious Processes of Nature Simply Explained
History
The Wonder Book of Knowledge: The Marvels of Modern Industry and Invention, the Interesting Stories of Common Things, the Mysterious Processes of Nature Simply Explained
Industrial arts -- History
At present the richest gold field in the world is that of South Africa,
which yielded in 1910 a value of $175,000,000, somewhat exceeding the
combined yield of the United States and Australia. Russia and Mexico
followed these in yield. The total production throughout the world
amounted to over $450,000,000, of which the United States produced
$96,000,000.
What are Cyclones?
A cyclone is a circular or rotatory storm, or system of winds, varying
from 50 to 500 miles in diameter, revolving around a center, which
advances at a rate that may be as high as forty miles an hour, and
towards which the winds tend.
Cyclones of greatest violence occur within the tropics, and they revolve
in opposite directions in the two hemispheres--in the southern with, and
in the northern against, the hands of a watch--in consequence of which,
and the progression of the center, the strength of the storm in the
northern hemisphere is greater on the south of the line of progression
and smaller on the north than it would if the center were stationary,
the case being reversed in the southern hemisphere.
An anti-cyclone is a storm of opposite character, the general tendency
of the winds in it being away from the center, while it also shifts
within comparatively small limits. Cyclones are preceded by a singular
calm and a great fall of the barometer.
What Metals can be Drawn into Wire Best?
The wire-drawing of metals depends on the property of solid bodies,
which renders them capable of being extended without any separation of
their parts, while their thickness is diminished. This property is
called “ductility.”
The following is nearly the order of ductility of the metals which
possess the property in the highest degree, that of the first mentioned
being the greatest: gold, silver, platinum, iron, copper, zinc, tin,
lead, nickel, palladium, cadmium.
Dr. Wollaston succeeded in obtaining a wire of platinum only 1/30000th
of an inch in diameter. The ductility of glass at high temperatures
seems to be unlimited, while its flexibility increases in proportion to
the fineness to which its threads are drawn.
How are Cocoanuts Used to Help Our Warships?
The fibrous husks of cocoanuts are prepared in such a way as to form
“cellulose,” which is used for the protection of warships, preventing
the inflow of water through shot holes.
The United States adopted the preparation for this purpose in 1892.
It is very light and compressible and when tightly packed between the
steel plating and the side of the vessel will expand when wet and fill
up the space through which a shot may have passed.
Another and cheaper product experimented with is the pith of the
cornstalk, which is much lighter than the cocoanut fiber and serves the
same purpose.
How did the Dollar Sign Originate?
Public-domain text, read in full here on John Shaqi.
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