GRAVEL MINING: BETWEEN THE SOUTH AND MIDDLE YUBA. 205 
washing, from 1870 to 1874, three and a quarter million cubic yards of fop- 
gravel, made a profit of $ 2,232.84, the yield per cubic yard having been only 
two and nine tenths cents; that of the Gold Run top-gravel having been 
four and seventy-five hundredths cents. This result led to some investigations 
in regard to the comparative value of the upper and lower portions of these 
gravel deposits; such investigations being considered desirable, in view of the 
large expenditures contemplated by the company, and, indeed, necessary, in 
case the lower gravels were to be worked. The following results are quoted 
from Mr. Smith’s report: “To test the comparative values of ground devel- 
oped by the shaft-workings and top-gravel, two hundred and forty samples, 
weighing in all two and one-half tons, were taken at even distances from the 
sides of the drifts, and the same quantity sampled from different layers of the 
upper bank. These samples were carefully panned out, and yielded, the blue 
$1.10 per ton, the white a large number of colors, but an inconsiderable 
weight of gold. The gold from the blue dirt was from fifty to one hundred 
times heavier than that from the white gravel.” It appears, also, that from 
every one of the 240 pans one or more colors of gold were obtained.* 
The following general summary of the economical results of hydraulic 
mining, in the region between the South and Middle Yuba, is extracted from 
Mr. Hague’s Report : — 
“The hydraulic method has now been in use on the ridge for over twenty years, and the expe- 
rience of this period affords some means of judging of the value of the gravel and the profit in 
working it. The general results have been very satisfactory. Wherever the richer blue gravel 
has been accessible, as at the Flats, Badger Hill, and below San Juan, it has, with very rare excep- 
tions, paid profits, and sometimes large profits, to its owners. The top-gravel, though much poorer 
than the blue, has often been found very rich in streaks (due to concentration by surface streams), 
and has, in general, paid large sums of money to the ditch companies furnishing the water, leaving 
something besides for the owners of the ground. There are few, if any, trustworthy records of 
operations showing in detail the costs and profits or losses of the business in the earlier years of 
hydraulic mining ; but so far as the top-gravel is considered, the price. paid for the water used in 
mining it is some indication of the result obtained. 
“Tn early years the price of water was twenty-five cents per inch, for ten hours’ flow. This 
price has fallen, by gradual reductions, to twenty, sixteen and two thirds, twelve and a half, ten, 
and eight cents per inch, for ten hours, the price at the present time varying from eight to twelve 
and a half cents per inch for ten hours, or twice that price for twenty-four hours. In many claims 
in which top-gravel only was washed, the water was paid for at twenty to twenty-five cents per 
inch for ten hours, and instances are reported in which, after paying these charges, the owners 
retained handsome profits ; such cases were, however, exceptional. On the other hand, it is well 
known that under the high rates charged for water in early days, many attempts to wash the top- 
gravel resulted in loss. 
* Mr. Bowie gives a section of shaft No. 1 in the Malakoff Diggings, in which the number of colors 
obtained at various points beneath the surface is stated. 
