SILVER MINING IN COLORADO. 605 



is very abrupt. The tunnel is 8 feet wide and 7 feet high. The rock passed 

 through has been comparatively soft, though granitic in character. At the 

 date just referred to, it had been driven 150 feet, entirely by hand, progress- 

 ing 2 feet per day, and, according to the best available information, at a cost 

 of $35 per foot. A complete outfit of Burleigh drills, air-compressing machin- 

 ery, and other appurtenances were on the ground, and about to be set up. A 

 vein, producing galena and zincblende, worth $100 to $200 per ton, had been 

 cut, but not sufficiently developed to aiFord much knowledge of its character. 

 The Marshall tunnel, the starting point of which is 50 feet above the bed 

 of Leavenworth Creek, pierces Leavenworth Mountain with a course of north 

 43° west. It is 7 feet high and 9 feet wide. In August, 1869, it had been 

 driven 320 feet, much of which passed through soft ground. The total cost 

 of driving, entirely by hand, is said by General Marshall, the superintendent, 

 to have been $26 per foot. In the distance then made, several strata, having 

 the appearance of veins, had been cut, but the indications of valuable ore were 

 not so great as to invite further exploration of them at that time, as it was 

 deemed more desirable to hasten on the prosecution of the tunnel as rapidly 

 as possible. Late accounts ^rom the work indicate that the tunnel has now 

 reached a point 700 feet from the mouth, and is in the immediate neighbor- 

 hood of the Equator lode. According to preliminary surveys this lode 

 should be cut by the tunnel at a depth of 350 feet below the surface. 



