THE COMSTOCK LODE. 15 



was made and the map drawn by Mr. James T. Gardner, first topographical 

 assistant. 



Before proceeding to the study of the detailed geology of the district a 

 word of reference is due to those who have preceded this Exploration in 

 investigating the Comstock lode and its surroundings. 



Ferdinand Baron Richthofen has published a pamphlet entitled "The 

 Comstock Lode: Its Character, and the Probable Mode of its Continuance 

 in Depth. San Francisco, November 22, 1865." 



This paper, by far the most important contribution to our knowledge of 

 the region, presents a brief sketch of the local geology and a quite detailed 

 account of the underground developments at that time. In describing it to- 

 day with all the light of four years additional work, the writer is unable to 

 confirm some of Richthofen's views, or rather predictions, as to the mode of 

 the continuance of the vein in depth, but this should in nowise detract from 

 the value of his instructive paper. A comparison of the. two investigations 

 will show exactly how far the present study accords with Richthofen and how 

 gravely it is opposed in some points. 



Mr. J. Ross Browne and Mr. R. W. Raymond, United States mining 

 commissioners, and Mr. R. H. Stretch, State mineralogist of Nevada, have 

 also given to the public their observations in official reports, but since they 

 are chiefly confined to a study of the economy and engineering of mines, 

 they will be more fully mentioned in the mining engineering report of Mr. 

 J. D. Hague, which immediately follows this chapter. 



The area represented upon Atlas-Plate II, lies wholly upon the eastern 

 slope of the Virginia Range. In the northwest corner is seen a flat, plateau-like 

 summit, from which, with a general direction toward the southeast, descends 

 a system of deeply eroded ravines. These gather themselves finally into two 

 main streams. Gold Canon and Six-Mile Canon. The upper portion of the 

 range sends out to the southeast lofty spurs which descend, with extremely 

 abrupt slopes, to the levels of Virginia City, Gold Hill, and American Flat. 

 Mount Davidson, the culminating point of this region, projects a spur which, 

 continuing southeast to the Carson Plain, divides the drainage of the district ; 

 all the water from its north side flowing into Six-Mile Canon, that from the 

 south into Gold Canon. Skirting the base of the first great step of the 



