CENTEAL AND EASTERN NEVADA. 381 



a return of 80 per cent, of the assay value. In the summer of 1869 the price 

 was reduced, partly owing to the competing influence of the Metacom mill, 

 to $35 per ton, with a return to the customer of 85 per cent, of the assay 

 value. It will be observed that the cost of working, at its lowest figure, is 

 but a trifle less, and is usually greater, than the custom price. The mill, 

 however, still has a margin of profit, under favorable circumstances, as the 

 yield of the ore often exceeds 85 per cent, of the assay value. 



The yield of the ores of the Manhattan mine, from September 30, 1866, 

 to January 1, 1868, varied from $111 24 to $255 77 per ton, coin value; the 

 average for 2,410 tons amounting to $186. From June, 1868, to August, 

 1869, inclusive, the number of tons of ore worked in the Manhattan mill, 

 produced by the Manhattan mine, was 2,087, having an average assay value 

 of $150 88, coin, yielding an average return of $133 44 per ton, or 88.44 per 

 cent, of the assay value. During the same period, that is, from June, 1868, 

 to August, 1869, inclusive, the total number of tons of ore worked in the 

 same mill, including the product of the Manhattan mine, with custom ores 

 produced in other mines of the vicinity, was 5,745, having an average assay 

 value of $247 99, and yielding an' average return of $217 31 per ton, or 

 87.63 per cent, of the assay value. 



The Metacom mill, which was engaged, in the summer of 1869, in work- 

 ing the ores of the Buel North Star, or Lane and Fuller Company, is situated 

 three or four miles from Austin. The process employed is the same, in its 

 essential features, as that already described, except that barrels are used 

 instead of pans for amalgamation of the pulp. The mill has 10 stamps, 

 weighing 900 or 1,000 pounds each. They drop 8 inches, 95 times per 

 minute, being lifted by a single-armed cam. The capacity of the whole bat- 

 tery is eight tons per day. 



There are four roasting furnaces, like those already described. The ore 

 contains a good deal of lead and zinc, and requires very gradual roasting, 

 involving the necessity of longer time than where these metals are less abun- 

 dant. Each charge of 1,000 pounds is in the furnace about eight hours, 

 giving a total capacity, for the four furnaces, of six tons per day. There are 

 six barrels, each having a capacity of 1,000 pounds per charge. They resem- 

 ble those, already described, at Dall's mill, but are moved by friction-gear. 



