102 GRAVEL AND PLACER MINING IN ALASKA. [bull. 263. 
ing water for hydraulic mining was making expenses. Some Nome 
operators are of the opinion that if crude oil can be obtained for $2 a 
barrel the gas engine can be profitably used to hydraulic certain rich 
patches of the coastal plain gravels, using 50 to 60 pounds pressure at 
the nozzle. Only under the most exceptional conditions would such 
an application of the hydraulic method be profitable. It may be truly 
said that 95 per cent of all attempts to pump water in hydraulic gravel 
mining, in whatever portion of the world they have been tried, have 
been failures. The miner who contemplates such an operation in a 
remote region where coal costs $30 a ton or wood $15 a cord had better 
first exhaust the possibilities of all other methods of moving gravel 
which circumstances or ingenuity can suggest. 
It must not be assumed that the tenor of the gravel in Alaska is 
greatly above that of the auriferous gravels formerly worked so 
extensively in California, especially where it is necessary, as in hydrau- 
licking, to distribute the value contained in the thin-bottom pay streak 
throughout the whole of the vertical section of gravel which must be 
moved. a There is a widespread opinion, amounting to a dictum, that 
the hydraulic method should be installed in preference to others 
wherever there is the slightest chance for its success. * That this chance 
is small in the hitherto developed portions of Alaska the present 
account will make clear. Capital invested by the miner in expensive 
water conduits in Alaska is not recoverable except from the profit on 
his operations. The ditch builder can not enter the domain of com- 
merce and sell his water or the power generated thereby, as do many 
of the water companies in populous agricultural and industrial com- 
munities. In rare instances only can he even sell it to miners. On 
the exhaustion of his own auriferous ground, his ditch and plant 
becomes practically valueless. 
While hydraulicking river and creek beds in Alaska with the neces- 
sary accompaniment of some form of lifting operation for the tailing! 
is not to be entirely decried, it should be undertaken with extreme 
caution. The ever-present danger of floods and the expense of wing 
dams must be considered. The tailings will be raised by the water lift 
primarily, and the method of using this in gravel mining will be fully 
described. The operator should bear in mind, however, that the 
introduction of the water lift decreases by over CO per cent the duty 
of the unmodified hydraulic method as above described; also that the 
"For example, Whitney states (loe. cit., p. 118) that the area hydraulicked off at Todds Valley, 
Placer County, Cal., was 1 mile by one-fourth mile in area, and the gravel from 35 to 75 feet in thick- 
ness, a total of nearly 9,000,000 yards, with an estimated yield of $4,000,000, or about 44 cents per cubic 
yard. 
At the Excelsior claim, near Placerville, Eldorado County, Cal., 20 acres of ground were washed 
off with an average thickness of from 40 to 60 feet of pay gravel. The yield was estimated at 
$5,000,000, about half of which was taken out by drifting and the other half by hydraulicking. Mr. 
Alderson, the principal proprietor, estimated that the yield of the Excelsor gravel was *1 per cubic 
yard. A single placer claim of 20 acres, containing so large an amount of gold as the Excelsior claim, 
has yet to be discovered in Alaska. 
