360 MINING DsTDUSTET. 



the surface, are very numerous, somewhat irregular as to course and dip, so 

 that their place in depth cannot be closely calculated, and many of them are 

 of doubtful permanency. 



Their width is also irregular, so that if one be cut in depth by a shaft or 

 tunnel, at a place where the walls are pinched together, it might be passed 

 without notice or identification. The faults, or slides, by which a whole series 

 of veins may be displaced, are also many, and are imperfectly understood. 

 The result is that when a vein is lost a search for its recovery may find one 

 or more veins, but without making it possible to decide very clearly as to the 

 identity of either of them. Under these conditions scarcely any of the com- 

 panies, mining at any considerable depth, have any positive assurance that 

 they are working on the same vein upon which their claims were located on 

 the surface. 



The field open for litigation under this state of affairs is very wide. In 

 effect, however, the number of companies working at present is very small, 

 the high costs of all mining operations having caused the suspension of work 

 on most claims; and the policy generally adopted by those who continue is to 

 take whatever they can get wherever they find it, until an adverse claim is 

 proved to be good; and this, under existing conditions, is not often practicable. 



The work of the Manhattan mine is a fair illustration of the general 

 method of operations in the other mines of the district, and its accounts prob- 

 ably furnish the most reliable data concerning the costs of mining and milling. 

 Some statements of this nature are given below, for which the writer is in- 

 debted to Mr. A. A. Curtis, the agent of the company at Austin. 



The vertical shafts, through which the work of the mine is carried on, 

 are about 12 or 13 feet by 4 feet, inside the timbers, divided into three com- 

 partments, two for hoisting and one for pumping. The ground is firm, and 

 the timbering consequently light, the shafts being lined with plank, without 

 heavy timber framing. Hoisting is done with cages similar to those in use in 

 Virginia City, already described. The water is raised from the bottom of the 

 Manhattan shaft by a six-inch force-pump. The power for hoisting and 

 pumping is furnished, at that shaft, by a steam-engine, having a cylinder of 

 12 inches diameter by 24 inches stroke. Friction-gear is used for hoisting, 

 and on. the same shaft which carries the drivers for the winding drums is a 



