192 SILVER-LEAD DEPOSITS OF EUREKA, NEVADA. 



cated as it was approached, although the indications were not so pronounced 

 that they might not have been caused by qualities of the rock independent 

 of the ore body itself. 



As yet no practical benefit has been derived either from the electrical 

 experiments or from the assays of country rock. This is partially due to 

 the fact that neither of those methods of search have been sufficiently de- 

 veloped to give definite results. As regards assaying, it may be said that 

 although the indications are often indefinite, this method can be carried out 

 with comparatively little expense and with little loss of time, though great 

 care must always be used in making the assays and in employing the re- 

 sulting values. 



FUTURE OF EUREKA DISTRICT. 



Future of Prospect Mountain. — The mining region of Prospect Mountain com- 

 prised between Spring Valley on the west and the Secret Canon road on 

 the east will no doubt produce large quantities of ore for years to come. 

 Though several of the mines of this portion of the district have been de- 

 veloped to a considerable extent, there remain a great many claims which 

 are still in a virgin state. Underground explorations have proved that 

 many of the deposits are continuous to a considerable depth. It is there- 

 fore very probable that numerous unexpected ore bodies will be discovered 

 throughout this region in the course of future deep prospecting operations. 

 The ore bodies of Prospect Mountain, however, are not likely to be as 

 large as those of Ruby Hill, owing to the structure of the country. Taking 

 into consideration the height of the mountain and the fact that no quantity 

 of water has been encountered even at a depth of over 800 feet, no trouble 

 need be anticipated from that source for some time to come. 



Future of the mines of Ruby Hiii. — What will be the future of the mines of Ruby 

 Hill is very uncertain, and any predictions in regard to it must necessarily 

 be inferred from the results of the explorations which have been made in 

 the present lower workings. These workings have not as yet given any 

 certain indications of the future. The probability of finding ore in the 

 lower wedge of limestone depends in a great measure upon the validity of 

 the theory of substitution. If this theory is the true one — and the proofs 



