50 GRAVEL AND PLACER MINING IN ALASKA. [bull. 263. 
On this subject Mr. Hamilton Smith makes the following state- 
ments: 
Soon after the discovery of gold in California in 1848 associations or incorporated 
companies were formed for the purpose of building ditches and storage reservoirs for 
the supply of water to the placer mines. The amount of capital invested in these 
hydraulic works aggregated many millions of dollars, and a single company often sold 
water to hundreds of mining claims. The cost of water was by far the most impor- 
tant item in the miner's bill of costs, and hence it became necessary to have a stand- 
ard measure, not only accurate but also so simple that the amount of discharge could 
be readily computed by the common miner. 
This was accomplished by the discharge of the stream of water sold to each cus- 
tomer through a rectangular, square-edged, vertical orifice, with free discharge into the 
air and having a constant head. In different parts of the State the standard open- 
ing varied, the width varying from 2 to 4 inches and the head above the top of the 
opening from 4 to 7 inches. Each square inch of the opening was called "a miner's 
inch;" hence in a locality where the standard opening was 2 inches wide, if the 
miner wished a flow of 50 miner's inches, the orifice was 25 inches long, and if only 
10 inches was needed the length was reduced to 5 inches. 
This method is analogous to the pouce d'eau used in southern France, and was 
probably first introduced or suggested in California by some French or Mexican 
miner; the simplicity of this mode of measurement, combined with a sufficient degree 
of accuracy, soon brought it into general use on the Pacific coast wherever water was 
sold for mining, irrigation, etc. 
The standard which had been in use since 1852 or 1853 in the mining districts 
supplied by the Eureka-Lake, Bloomfield, and Milton water companies in Nevada 
County, Cal., was an opening 50 inches long, 2 inches wide, with constant head above 
opening of 6 inches; the flow from this was called 100 miner's inches. * * * 
Generally the miners bought water for ten hours per diem at an agreed price per 
inch; for example, a miner using 350 miner's inches, for ten hours each day, at the 
rate of 15 cents per inch, paid the water company $52.50 per diem, and received the 
amount of water which would flow through an orifice having an aggregate length of 
175 inches, a width of 2 inches, with a head of 6 inches above the top of the open- 
ing, during a period of ten hours. 
When water was used for the whole twenty-four hours of the day the flow was 
termed "a miner's 24-hour inch," and, of course, meant 2.4 times the amount of dis- 
charge of "a miner's 10-hour inch." 
In California, as larger amounts of water eame into use, wider open- 
ings were adopted, one being 12 inches high, 12f inches long, with a 
constant head of 6 inches above the top of the opening. 
Experiments made in California by A. J. Bowie, esq., 6 to determine 
the value of the miner's inch, defined as the one two-hundredth part j 
of the quantity of water which would flow through the last-named 
aperture in a l^-inch board under head of 6 inches above the top of 
the discharge, showed that 1 miner's inch discharged in — 
Cubic feet. 
1 second 0. 02499 
1 minute 1. 4994 
1 hour 89. 9640 
24 hours ; 2, 159. 1460 
" Hydraulics, 1886, p. 277. 
*> Bowie, A. J ., jr., A Practical Treatise on Hydraulic Mining, 1885, p. 126 
