Page:Popular Science Monthly Volume 41.djvu/373

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It would be impossible to even enumerate the many inventions that have been made to save hand labor and hasten the various processes of finishing. Among the most serviceable is the scouring machine. When the leather is taken from the vats it is usually covered with dust and sediment and stained with resinous matter. Formerly these defects were removed by hand with brush, stone, and slicker; now, however, it is done by "scrubbers" and scouring machines. There is a variety of these, but in general they consist of a level table or platform which is freely movable in all directions. Mounted above it is a reciprocating frame, in which are fixed brushes and pieces of slate and thin stone. By the movement of this, with a small jet of water, the whole surface of the leather is scoured and brushed. Another invention—this to replace the work of the currier in paring and evening and bringing out the grain of the leather—is the whitener. Essentially this machine is like a lawn-mower. It performs its work through the cutting action of a small cylinder with sharp, oblique edges. The cylinder itself moves to and fro over the leather while the knives revolve at the rate of two thousand times per minute. In the machine invented by Mr. Charles Korn, one of the most skillful leather-finishers in the country, these knives are fastened to an endless leather belt, and are set diagonally, so that when the cut is made on the beam as it passes down in front of the operator it is a sliding one. The knives are cleared on the edge by an automatic finger and sharpened by an automatic hand. In the Union leather whitener the belt contains thirty-two knives, while the cylinder revolves 2,780 times per minute, and the pendulum swings to and from the operator at a speed of ninety a minute. These machines can do the work of from four to eight men, and do it as well. Still another finishing machine is the stuffing-wheel, by which the tallow and oil are worked into the leather. This was patented in this country in 1855 by L. W. Fiske, of Louisville, Ky., though it had been previously used in France and Germany. The crude idea of a stuffing-wheel is a revolving hogshead into which the leather and grease are put and a current of steam or heated air passed through. The success of this wheel did much to revolutionize the character of the upper leather of this country. By it the oil and tallow were worked into the center of the fiber, thus making the leather soft and yielding instead of stiff and hard as of old. These devices nearly all had their origin about the time of the civil war, when workmen were scarce in the North, and when manufacturers had to turn their attention to some means of supplying the deficiency.

In point of importance, next to the invention of the splitting machine, stands the discovery of a method for utilizing spent wet