92 



The mines are worked both with the pickaxe 

 and by explosion. The ore is reduced to pow- 

 der in a mill of a very simple construction^, 

 called trapicJie, of which two stones, the lower 

 placed horizontally, and the upper vertically, 

 form the mechanism. The horizontal is about 

 six feet in diameter, and has near its circumfe- 

 rence a groove of eighteen inches deep, in which 

 the ore is placed ; through the centre passes a 

 perpendicular cylinder c(^nected with a cog- 

 wheel turned by water. The vertical stone is 

 about four feet in diameter, and ten or fifteen 

 inches thick, and is furnished with a horizontal 

 axis, which permits it to turn freely within the 

 groove. When the ore is sufficiently pulve- 

 rized, a proportionate quantity of quicksilver is 

 added to it, which is immediately amalgamatecj 

 with the gold ; io moisten the mass, and iuT 

 corporate it more fully, a small stream of water 

 is then directed above it, which also serves to 

 carry off the amalgam into reservoirs placed 

 beneath the stone. The gold combined with 

 the mercury falls to the bottom of these reser- 

 voirs in the form of whitish globules ; the mer- 

 cury is next evaporated by heat, and the gold 

 appears in its true colour, and in all its bril- 

 liancy. In each of these mills upwards of two 

 thousand weight of ore is daily ground and 

 amalganjated. 



As the digging of the stone ore obtained froni 



