35+ THE POPULAR SCIENCE MONTHLY. 



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 host- 

 less though not homeless, were provided with roofs and shelter. 

 From 1830 to 1836 we adopted several improvements in manufact- 

 uring, 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 pat- 

 ented in this country, having been known in Pennsylvania, Mary- 

 land, 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, confu- 

 sion, 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 



