84 [APPENDIX 



amalgamating apparatus is not of sufficient capacity at present to dispose of 

 that amount of ore judiciously, the amalgamating instruments consist of 

 Cram's Cylinder and Berdan's Amalgamator, in the latter about fifteen per 

 cent of the gross amount is saved after it has passed through the other in 

 struments ; this arises from the fact that Berdan's instrument possesses a 

 levigating power from revolving balls in the instrument which gives a new 

 surface to the material passing under them. 



GOLD HILL MINE. 



This mine is located in the town of Grass Valley on the first hill to the 

 west of the village. The mine was first opened in- 1851 and worked to a 

 considerable extent and profit, subsequently it passed to the hands of the 

 Agua Frio Company under the superintendence of their agent Mr. Atwood 

 in whose possession it now remains ; after an examination of the mine the 

 old method of working was given up, and a new system of operations en 

 tered upon in order to tap the vein at the lowest possible point and at the 

 same time afford easy transit to the reduction works and drainage to the 

 mine. With this view an adit was commenced about fifteen feet above the 

 level of the creek which flows in front of the town, and carried west through 

 the base of the hill for a distance of seven-hundred feet, cutting through 

 allavium and decomposed granite most of the way, at the west end of the 

 adit which cuts the vein nearly at right angles, the shaft marked A in the 

 longitudinal section was intersected at a depth of ninety feet below the sur 

 face ; from near the ninety feet shaft a level has been driven to the north 

 on the strike of the vein about seventy feet marked, I), also two other levels 

 east of it, E, F, which intersect the north crosscut D of the ground plan ; 

 a winze has been sunk below the water level sixteen feet marked H, of the 

 longitudinal section ; this disposition in the working of the mine affords 

 many advantages in the extraction of the ore and attle and easy communica 

 tion with all parts of the mine and surface, and the intersection of the shaft 

 A produces ample ventilation. 'The vein intersects the greenstone at the 

 bottom of the air shaft, and as in the case of the Lafayette has cut com 

 pletely through it ; increasing in power as it enters this rock, about one 

 thousand tons of ore was in the yard at the time I visited the mine ready to 

 pass through the reduction works. From the end of the long adit a tram 

 road four-hundred feet in length passes to the mill on which by mule power, 

 the ore is conveyed from the farthest part of the mine. The ground plan 

 exhibits the crosscuts and levels and their connection with the mill. 



The strike of the vein is north and south diping east at an an angle of 24 

 degrees, with a vein whose power at ninety feet was nearly three feet ; the 

 transverse section is shown the air shaft entering the greenstone and inter 

 secting the vein, with the increase in power of the vein from the surface to 

 the lowest point worked. The ores in the greenstone differ in no particular 

 from those of the Lafayette, with the exception that none of the plumbic 

 sulphuret was observed at this mine though the vein has much the* same 

 blue tint. The reduction works of this company were not completed in No 

 vember and no opportunity was afforded to witness their process at that time ; 

 it was expected that their machinery would be capable of reducing over one 



