Page:Popular Science Monthly Volume 41.djvu/368

354 few of the hides one day to a fulling mill that was near. The result of that venture was the hide mill. The work of Colonel Edwards was amplified and supplemented by others, until the leather industry had become one of the most firmly established in the country. Of these changes Mr. Pratt, to whom reference has been made, said in 1859:

"From 1815 to 1835 tanneries, which had previously been hostless though not homeless, were provided with roofs and shelter. From 1830 to 1836 we adopted several improvements in manufacturing, among which was a change in the method of unhairing the hides. Discontinuing the use of lime, we adopted, for sole leather, the process of sweating, a method which was falsely patented in this country, having been known in Pennsylvania, Maryland, and Germany. Another improvement was the substitution of fulling or softening in the hide mill in place of the old process of soaking and breaking over the beam. We also discontinued the wasteful operation of skiving, and by these improvements we succeeded in producing at less expense a larger quantity and a better quality of leather. The old method of thrashing the bark was replaced by the rotary grinding stone, and this plan in turn was replaced by the bark mill, invented by Tobey and others, worked at first by horse-power and afterward by steam and water power. As the principles of tanning became better understood, the bark was ground fine, instead of coarse, as before. The old lever pump made way for the press and screw pump; the old slicker of wood, stone, or glass gave place to the rollers made of brass. The water, also, was no longer applied cold to the bark, but heat was added to the leaches, by heaters, pan and steam, and thus the tannin was more effectually extracted. Larger leaches came into use, and the leather was put through a series of baths containing ooze of different strengths. Manual labor gave place to the more economical force of steam and water power. The change from the tanneries of the past to those of the present may be described as a change from chaos to system, from waste, confusion, and long delay, to method, economy, order, and dispatch."

These changes are represented in the hide mill, the bark mill, the splitting machine, the stuffing-wheel, the scouring machine, and the boarding machine. The hide mill was the invention, or rather adaptation, of Colonel Edwards, of Northampton, to whom reference has already been made, and the patent granted him by the Government bears the date of December 30, 1812. The next patent on this mill was not taken out until 1867, the patentee being Mr. J. M. Brown, of Boston, thus showing how comparatively few and slow were the changes in it. The object of these mills is to soften the tough, dry hides so as to render them not only easier of manipulation but readier to absorb the tannin. The mills, as