OILS 



437 



The edge-mill, for grinding seeds, is represented in fig. 1569. p is the water-wheel, 

 which may drive several pairs of horizontal bevel-wheels working in q, q, and turning 



1569 



the shafts, s, s ; t, t, two horizontal spur-wheels fixed to the upper part of the vertical 

 shafts, and driving the large wheels, u, u. To the shafts of these latter wheels are 



1571 



1570 



fixed the runners, v, v, which traverse upon the bed-stone, w, w ; x, x, are the curbs 

 trarrounding the bed-stone, to prevent the seeds from falling off; o, is the scraper. 

 Mill A represents a view, and mill B, a section of the bed-stone and curb. Some hoop 

 the stones with an iron rim, but others prefer the rough surface of granite, and dress 

 it from time to time with hammers, as it becomes irregular. These stones make from 

 30 to 36 revolutions upon their horizontal bed of masonry or iron in a minute. The 



