DOWN IN A MINE. 123 



a grade of one inch in 100 feet. In the bottom is a drainage 

 channel five feet wide and three and one-half feet deep. After 

 the mining companies began pumping water into the tunnel, 

 over three and a half million gallons were discharged every 

 twenty-four hours. During 1880, the aggregate was over a 

 billion and a quarter gallons, and it was estimated that double 

 this quantity would be discharged when connection should be 

 made with all the mines. The temperature of the mixed 

 water entering the drain is 137, and its temperature at the 

 mouth is 118. Little use is made at present of this stream 

 of water, amazing equally for volume and for temperature. 

 It is apparent, however, that this vast stream of hot water 

 possesses capabilities of usefulness which American enterprise 

 will not permit to run to waste indefinitely. 



During twenty years, up to 1881, the bullion yield of the 

 Comstock Lode had been $306,000,000. Since 1874, business 

 on the lode has been much depressed. 



Investigations have been made for the purpose of ascer- 

 taining the source of the precious metals in the lode. Mr. 

 George F. Becker has shown the presence of gold and silver 

 in the unaltered diabase rock on the east of the lode, and 

 demonstrated it practically absent from that part contiguous 

 to the lode which has undergone decomposition. It results 

 from his studies, that after the region had been shattered by 

 earthquake disturbances, floods of heated waters rose through 

 the rocks, carrying carbonic and sulphydric acids, and satur- 

 ating the east country, dissolving out silica and metallic salts, 

 and redepositing them again in the spaces comparatively open. 

 He finds by calculation that the total metal taken from the 

 lode is not in excess of that originally contained in the 

 diabase on the east, within the region now occupied by the 

 decomposed rock. 



This explanation will apply to the accumulation of ore in 

 veins of a more typical character. The Comstock Lode can 

 scarcely be called a "true vein" in the accepted sense. A 

 vein proper is a fissure extending to a great depth in the earth, 

 and having generally a considerable longitudinal extent, with 



