The machine is provided with a pair of rolls at each end of the bed, which are adjustable for different lengths of shaft, and are made to revolve by power applied through suitable gearing and a splined rod inside the bed; the bar of iron being placed on the periphery of the rolls receives a rotary motion by friction, and shows the crooked places in the same way and with the same ease as though rotating on centers in the usual manner; vertically adjustable blocks are arranged in the base of the press to support the iron; power is applied by means of gearing to a splined rod at the back of the machine, on which is a sliding clutch connecting, at the will of the operator, with an eccentric; the eccentric conveys motion and power through a link to the elbow joint at the front of the press, which forces a plunger down against the iron.

[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.  And for similar explorations in the same class of depositions we have the experiences of our own times, and which explain by comparison all the previous operations alluded to.