THE COMSTOOK LODE. 55 



new fissure has developed itself to the east of the old one. Starting from the 

 surface trace of the east clay, the new fissure descends nearly vertically to the 

 400-foot level, where it curves rapidly to the east, projecting indefinitely 

 downward at a general dip of 40°. 



In contact with the east wall, downward from the 480-foot level, has 

 existed a vein of white quartz, having an average width of 70 feet, but con- 

 tracting on the 750-foot level to 40 feet, and again on the 1,100-foot level 

 pinching to about the same breadth. 



Where the quartz first made its appearance it curved eastward, approach- 

 ing a horizontal position, and including a large body of ore. 



This ore has occupied a zone on each side the quartz, whose central por- 

 tions have never carried a workable percentage of silver. The same irruptive 

 dike which was noticed in the middle levels of the Potosi section occurs in 

 the Hale and Norcross, rising to different heights along the west wall, appear- 

 ing with more or less regularity down to the 1,000-foot levels. From the 

 535-foot station down to the 750, a seam of quartz crosses it diagonally. The 

 red vein, forming the western mass and corresponding to the great body in the 

 Chollar-Potosi shaft-section, is here never richly mineralized. In the early 

 days of Washoe mining it was rejected altogether, but under the present 

 stimulus of cheaper costs of mining and milling it is yielding a fair profit. 

 The character and average silver tenure of these poorer parts of the lode are 

 the most difficult points to consider; all ore selections are made by the 

 miner's eye, the constantly changing percentages in the rock defying a 

 general estimate. The only true value is gotten by mill returns. 



By referring to Atlas-Plate 11, it will be seen that the section on the 

 331-foot level shows the red vein and the remarkable fact that it leaves the 

 east wall and traverses the horse material, joining the west wall at the extreme 

 western angle of the recurve. The west country in the Hale and Norcross 

 inclines to the east at a rather gentler angle than in the more southern claims. 

 Quartz, propylite, andesite, and clay are all alike impregnated with brilliant 

 crystals of iron pyrites. 



The three sections of Atlas-Plate 9 illustrate every important fact in 

 the southern half of the Virginia group excepting the existence of two syenite 

 horses, which appear on Atlas-Plate 11. In the Bullion and the southern part 



