THE REGION BETWEEN SMARTSVILLE AND FRENCH CORRAL. 383 
The grade is given in inches for every twelve feet of length. The tunnels above mentioned all 
discharge directly into the South Yuba, except the last, which discharges into Deer Creek. 
In addition to these the Blue Point tunnel should be mentioned, which is said to be 2,270 feet 
in length, and the branch tunnel which the Excelsior company is now driving in order to make an 
outlet for the Smartsville Consolidated gravel through the Blue Gravel tunnel. This list differs in 
many respects from that published in Raymond’s report for 1873, page 131, but is probably a cor- 
rect statement in regard to the tunnels now available for use. 
The data in reference to the yield of gold at Smartsville, taking the district as a whole, or the 
yield per cubic yard of gravel, are too vague to be of much value; but there is no doubt that the 
gravel has been of unequal richness in different portions. The north rim, for instance, has paid 
better than the south. The ground of the Blue Gravel claim has been noted for its great yieid of 
gold, while the claims lower down have been comparatively poor. In Raymond’s report for 1875, 
page 97, it is stated that the gravel worked by the hydraulic process had yielded up to that time 
“ $7,000,000, exclusive of $3,000,000 which was taken out in the early days, before the era of 
deep mining.” This statement is in harmony with what 1 was told by Mr. O’Brien, who estimates 
the total yield up to the time of my visit at $13,000,000. Assuming these statements to be 
approximately correct, and adopting also the results of Mr. Bowman’s measurements of the ground 
worked out, the average yield of the Smartsville gravel amounts to about twenty-three cents per 
eubic yard. 
As to the amount left to be washed by the hydraulic process, I can only say that I have Mr. 
O’Brien’s estimate of from $18,000,000 to $ 22,000,000 as the probable yield in the future. 
The gold at Smartsville is fine, a nugget worth as much as five dollars being seldom found. In 
quality the finest grains are the best, reaching sometimes a fineness of .978. The average fineness 
of the Mooney Flat gold may be taken as .928. 
I will add here a few notes taken at Smartsville, though not directly appertaining to what has 
gone before, or which are not sufficiently complete to justify any detailed statements. 
The experiment of illuminating the banks at night by means of the electric light has been tried 
with considerable success at the Mooney Flat mines. The Brush machine is used, the power em- 
ployed being water-wheels, driven by water taken from the company’s ditches. 
White labor is employed exclusively at Smartsville. Portions of bed-rock, partially cleaned, are, 
however, leased for limited periods of time to Chinamen, who pay a certain price for the privilege 
of working. ‘The nozzles in use at Mooney Flat were 64 inches in diameter, two in number, each 
using 550 inches of water. The Smartsville inch of water is measured through an orifice four 
inches high, the level of the water being eight inches above the top of the orifice. 
I made inquiry as to the existence of gravel beds to the north and west of Smartsville, and was 
told that there were none between Sicard Flat and Bangor, but that at the latter place and at 
Hansonville there were or had been gravel mines in operation. Time did not allow of my visiting 
the places, and I do not think them of much importance. Mr. O’Brien also mentioned Ohio Flat, 
near Forbestown. I was not able to go there. There-is a short reference to the place in Ray- 
mond’s report for the year 1872, page 71. 
Section II.— Zhe Region between Smartsville and French Corral. 
No work of any importance has been done in this region, and no new discoveries have been 
made since the time of my visit in 1870, so far as I can learn. The tunnel at Pearl’s Hill* has 
been driven in far enough to demonstrate the presence of gravel under the capping of lava, but the 
deposit cannot be worked without increased water facilities. Mr. Pearl told me that the gravel 
struck in the tunnel was reddish in color, and not cemented. He expects to be able to work 
a bank of a hundred feet in height at some future day. The diagram (Plate N, Fig. 3), from 
* See ante, p. 195. 
