[Illustration: POWER STRAIGHTENING MACHINE.]
Sufficient adjustment is provided for different sizes of iron by turning a
nut at the top of the press.
Any point in the length of the bar can be reached by moving the press on
the bed. Any length of iron can be straightened, and the most laborious
and disagreeable work in the process of making shafting is rendered easy
and rapid. Made by Wood, Jennison & Co., Worcester, Mass.
* * * * *
HYDRAULIC MINING IN CALIFORNIA.
By GEORGE O'BRIEN.
Our knowledge of the primitive operations of the aboriginal inhabitants of
the globe in pursuit of gold is barely traditional, as we are only aware
that from very early times the precious metal was collected and highly
prized by them, and that they chiefly extracted the visible gold, which
existed in prodigious quantities on or closely beneath the surface of the
earth, and of its being particularly abundant in Asia and Africa. But we
can draw more positive conclusions as we survey remains of the rude but
effective contrivances used by them in later, but still remote, periods,
with full evidence as to the extent of their operations, in the numerous
perpendicular shafts located at short distances from each other, over
large areas of auriferous gravel in India, as well as from precisely
similar memorials of ancient workings which remain also further
demonstrations, in the abandoned "hill diggings," and shifted beds, and
beds of rivers, in Peru South America, flowing between the sea and coast
ranges of the Andes, descending in a northeasterly direction to the river
Amazon, and that their much coveted and enormous productions were the
accumulated riches of the Incas, transferred as spoils of war to their
Spanish conquerors in the sixteenth century.
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