600 MINING INDUSTRY. 



the middle tunnel being about 200 feet, and the third, or lowest, being over 

 400 feet in length. These adits are connected by winzes. The amount of 

 stojDing that had been done, at the date referred to, was comparatively small. 

 From these openings small lots of selected ore had been obtained that 

 had yielded from $200 to $300 per ton. The lower grade, or common ore, 

 yielded from $50 to $100 per ton. Up to the date referred to no very large 

 amount had been worked, as the company's mill had not then commenced 

 operations. The total product of the ores treated is said to have amounted, 

 at that time, to about $6,000 ; besides which about 200 tons of common ore 

 were awaiting treatment in the company's mill. The construction of this 

 estabhshment was begun early in 1868, but owing to changes of plan and 

 other hinderances it was still unfinished in the autumn of 1869. The pro- 

 cess at first selected was that of smelting with lead and subsequent cupella- 

 tion, for which method the furnaces were built ; but as the ore proved to con- 

 tain a lower percentage of lead than is requisite, this was discarded and the 

 chloridizing-roasting, with barrel amalgamation, was adopted. Some details of 

 this method will be given further on. The mill consists of crushing 

 machinery, which comprises one Dodge crusher and two Ball pulverizers ; 

 three of Briickner's revolving cylinders for chloridizing-roasting; six barrels 

 for amalgamation ; a retorting furnace, and other appurtenances necessary for 

 the business, including two excellent steam-engines, the cylinders of which 

 are 14 inches by 30, geared together to drive all the machinery. Two large 

 boilers supply steam. 



The left-hand fork of the stream above Greorgetown has been as actively 

 explored, at least for a portion of its length, as the right-hand fork. The 

 course of this stream, from its head- waters to its confluence with the other 

 fork at Georgetown, is generally from the southwest to the northeast. The 

 principal mining developments have been made in the hills which rise between 

 the two streams. Of these hills, that which is known as Leavenworth Moun- 

 tain has, thus far, been the scene of the most active operations, 



Equatok. — The Equator mine, on a lode of the same name, is, at present, 

 the most prominent mining enterprise in this neighborhood ; the Winnebago, 

 on the same lode, and the Argentine, McClellan, Gilpin, and others, in the 

 vicinity, are of growing importance. The Marshall, tunnel is also in this hill, 



