262 MINING INDUSTEY. 



lishments in the district engaged entirely in working over the tailings of the 

 crushing mills. Some of the smaller ones are situated in the canons or in 

 the immediate vicinity of the mills which furnish their supply, but the most 

 important are placed near the large reservoirs just described and draw from 

 them the material for their work. The largest of all the mills thus engaged 

 is that of Mr. Birdsall, at Dayton. This mill was formerly a crushing mill, 

 provided with 30 stamps and 20 Wheeler pans. It has lately been refitted 

 and devoted to the working of tailings. The stamps, of course, are useless 

 for this purpose. A number of large Horn pans have been added to the 

 machinery of the mill, making 30 or 35 pans in all, with capacity for work- 

 ing between 250 and 300 tons of tailings per day. The mill has an excel- 

 lent water-power, derived from the Carson River, ample for all its needs. 

 As it is conveniently placed with reference to the supply of material, it 

 should be able to do its work very economically. It is said that the business 

 of this mill is exceedingly profitable, but the writer is not in possession of 

 definite information concerning the yield of the tailings or the costs of work- 

 ing them. 



In the neighborhood of the' Birdsall mill, also at Dayton, and engaged 

 in working tailings from one or more of the reservoirs there, is the mill of 

 Messrs. Janin and Baldwin. This mill has five McCone pans, with a capa- 

 city of about 50 tons per day. It is driven by steam, an engine of 12-inch 

 cylinder doing the required work. Each pan works a charge of 4,000 or 

 5,000 pounds ; and four or five charges per day, making a full duty of 10 

 tons per pan for each 24 hours. 



Sulphate of copper and salt are supplied to the pans with each charge ; 

 the former reagent in quantities varying from 3 to 6 pounds per ton of tail- 

 ings, and the latter largely in excess, from 20 to 30 pounds per ton. The 

 pans are covered, and supplied with steam, keeping up a high temperature. 

 The yield obtained is thought to be about sixty per cent, of the assay value, 

 which is said to average $16 or $18 per ton. From the accounts of this mill, 

 furnished by the kindness of Mr. Baldwin, it appears that during five months, 

 ending October 31, 1869, the quantity worked was 6,732 tons; of which the 

 average yield was $9 75 per ton. The total expense of the mill during these 



