Eiv-reioir. 



T^^t/ '^r'^ 



.fft:^r n'fr /•" ^/ . V/, 





f y ^^/-^ »#^' Jii^*f*fM//f ^f. 





/ 



,..««-»*. /..w,<--^. 



-/-5!:*«y 







( :.^^^^;^^^i^:$*-L/:^^ 



<1gure 2. — Pryor's Bark Mill. This patent drawing of May 21, 1805, reveals 

 that the earliest mechanical adjunct of leather manufacture had remained basi- 

 cally unchanged from 1660. John Bigelow in 1842 described a mill in which 

 bark was either "cut with knives, beaten with hammers, and ground with 

 stones or cylinders," but even then the bark mill used by the .American tanner 

 retained its early form. 



