16 MmiNG INDUSTRY. 



mountain descent is a comparatively level region, and at the junction of this 

 steep summit slope with the plateau is the Comstock lode. 



About four miles to the east, and, in general, parallel to the summit, rises 

 a lofty ridge, whose most prominent points have been called Mount Kate, Mount 

 Rose, and Mount Emma. 



The surface of the district is rendered extremely rough by a labyrinth 

 of canons, which are deeply cut in all directions. An idea of their depth 

 may be gained by a brief study of the contour lines of the map. For 

 instance, the vertical distance from the central street of Virginia to the sum- 

 mit of Mount Davidson is about 1,700 feet, and from the bottom of Six-Mile 

 Canon, opposite the Sugar Loaf, to the summit of Mount Emma, is 1,300 feet. 

 The Gold Canon, just above Silver City, 700 feet. The slope of Cedar Hill, 

 from its summit to the Geiger grade, which may be seen following an approxi- 

 mate grade curve, is 1,100 feet. Nearly all the lesser ravines will average 300 

 feet in depth. 



The following list of altitudes of several important points in the district 

 conveys a general idea of the average elevations, expressed in feet : 



Mount Davidson 7,827 



Virginia Oity^ Street 6,192 



Summit Cedar Hill 7,235 



Pass at liead of Gold Canon , 7,527 



Gold HiU Divide 6,366 



Quarry Hill, Virginia City 6,462 



Cone east of Gold HiU 6,240 



Pass of American Flat grade „ 5,886 



Sugar Loaf 6,164 



Mount Kate , 6,187 



Mount Eose , 6,448 



Mount Emma 6,546 



Signal Peak on ridge north of Sugar Loaf 6,621 



Devil's Gate 5,105 



Carson Plain. 4,700 



Washoe Plain 5,106 



Looking from Virginia, the ridge, culminating in Mount Emma, nearly 

 closes the eastern view, except where the deep cut of Six-Mile Canon opens 



