164 MIMNG INDFSTEY. 



district, is the Sutro Tunnel. This scheme proposes the construction of an 

 adit or horizontal tunnel, which, commencing in the eastern foot-hills of the 

 range containing the lode, at a point in the valley of the Carson River and 

 about 150 feet above the level of the stream, shall pierce the intervening 

 country -rock vt^ith a westerly course, and, reaching the lode at a distance oi 

 about 21,000 feet from the place of beginning, cut it at a depth of nearly 

 2,000 feet below the outcrop. 



The advantages of such a tunnel in the exploitation of the lode at a 

 great depth have been plainly set forth by the projector of the enterprise, 

 and consist chiefly in the facilitation of drainage and ventilation of the mines, 

 and the transportation of ores, waste-rock, materials and men between the 

 mines and the surface ; in addition to which there would be the incidental 

 and important advantages of opportunities afforded thereby for the further 

 exploration, not only of the lode, but of the country lying east of it, to be 

 passed through by the tunnel. 



By affording this means of drainagCj and thus relieving, as it would 

 to a great extent, the necessity foi" pumping machinery and its operation, a 

 great item in the cost of mining would be dispensed with ; while the water 

 accumulating in the vein above the level of the tunnel would be available 

 for power for raising both water and ore from depths below. 



It is proposed to construct this tunnel about 12 feet square, in section, 

 providing it with a double railroad track foi' the passage of cars to and from 

 the mines ; the cars to be moved by means of a wire rope and a stationary 

 engine at the mouth of the tunnel. 



The main tunnel, to reach the lode, will have a length of about 21,000 

 feet ; and, from the point of its intersection with the lode, lateral drifts will 

 be run north and south in order to render the workable ground of the whole 

 lode accessible by means of the tunnel, affording to all the mines along its 

 length, and connected with it, the facilities of drainage, ventilation, and 

 transportation. The aggregate length of these lateral branches will be be- 

 tween 15,000 and 20,000 feet. 



It is proposed to sink four shafts along the course of the tunnel, from 

 the surface to the tunnel-level, for the purpose of expediting the work by 

 multiplying the points of attack and also to afford ventilation. The aggre- 

 gate length of these proposed shafts is about 4,000 feet. 



