236 B. Silliman on the Grass Valley District. 
Art. XXVII.—Notes on the Grass Valley Gold-mining District; 
: by Prof. B. Srmumman. 
Grass VALLEY Disrricr has obtained a well-earned celebrity 
as the most prosperous of all the gold-quartz mining districts in 
California. Quartz mining was begun here as early as 1850, and 
been continued with, on the whole, a steadily increasing suc 
cess, to the present time. 
It is difficult to obtain exact statistics of the total product of 
the Grass Valley quartz mines, but it is believed by those best 
able to form a trustworthy opinion on this subject, that the pro- 
duct in 1866 was probably not less than $2,000,000, while for the 
whole period froma 1851—say fourteen years—it was probably 
in excess of $23,000,000. fe 
Wn. burner, Esq., in his remarks on the gold mining 
e Rocky Moun 
of the Grass Valley region (page 46) thus: __ 
When we consider the richness of the veins, the length of time 
cana ae “ee — been worked, and the amount of gold 
annually produced, the most important quartz mining region 
California is, without any doubesdhnt of Geum Valley, in Nevada 
county. Here mines have been worked uninterruptedly since 
1851. Itis true there have been periods when the interest Was 
more than usually depressed, and several of the mines, which 
; NOW vi 
in many 
instances where work was resumed new bodies of gold-bearing 
quartz were opened up, which proved rich and valuable. The 
most productive, are noted for their narrowness, as well as 
the richness of the quartz, They are encased in a hard 
Sires a has produced more than ag 
“er. a foot or fourtee u sie rie gaind ian egos 
ld bearing rocks at this place are mostly highly met 
