Page:Popular Science Monthly Volume 41.djvu/367

 clayey side of a hill for its location. There was a fine spring of water just above his vats, and the natural flow of it was enough to keep them filled. Colonel Edwards's first improvement on the tannery of the day was the making of a place beneath the vats for carrying away the spent liquor. The Ogden and Spencer tannery, it will be remembered, had no provision for getting rid of





 —A great variety of machinery has been introduced for finishing the leather after it has been tanned. Most prominent among them are those figured above. The object of the boarding machine is to bring up the grain and give a granular appearance to the leather. The other machines are for the details of the process.

that refuse. Colonel Edwards, too, arranged his leaches in tiers, one above the other, and used a suction-pump for raising the liquor. He built a mill for grinding his bark, and, instead of the customary horse as motor power, used water. Perceiving that his leather tanned faster in summer, the application of heat was suggested, and the result was the invention of the copper heater. Dry hides had become very plentiful at that time, and Colonel Edwards had used a stone wheel to soften them. This, however, was a slow operation, and as an experiment the colonel took a