the desired thickness by hand, entailing obviously a great waste not only in time but in the large portions of the hide which it was necessary to throw away. By the use of these machines, however, these same hides may be split into two, three, or even five parts, of such thickness as is desired, and each part rendered available. This machine was not really perfected until about 1860. As early as 1800 rough attempts had been made to split leather by machinery, and in 1809 Seth Boyden, of Newark, N. J., secured a patent for such an invention. But there were serious obstacles which
Fig. 17.—Bark Mill.
rendered it impracticable, and it was left to the ingenious mind and skilled hand of Alpha Richardson, of Boston, to overcome them. He secured his first patent in 1831, but he continued to make improvements upon this device until 1856. Then all were grouped, and what is known as the Union splitting machine was the result. This machine is the one which is now in common use among American tanners. Its machinery is somewhat complex. It consists of a small cylinder upon which is placed the hide or leather to be split. As this cylinder turns, the leather is drawn against a sharp knife firmly bolted to the bed of the machine. Above the knife is a stiff spring which holds the leather closely to the edge of the blade, and a gauge-roller, which by means of
