miner’s inch

In the western United States and Canada, and in New Zealand, late 19th – early 20th century, a unit of stream flow used by miners. The size of the unit varied greatly from place to place.

New Zealand 60 cubic feet of water per minute

Elwyn E. Seelye.
Data Book for Civil Engineers. Vol. 2. Specifications and Costs.
New York: John Wiley, 1951.

British Columbia 1.68 cubic feet of water per minute

Alfred H. Ricketts.
American Mining Law with Forms and Precedents. 4th ed. enlarged and revised.
California Division of Mines Bulletin 123,  Feb. 1943.

Colorado 1.56 cubic feet of water per minute

Alfred H. Ricketts.
American Mining Law with Forms and Precedents. 4th ed. enlarged and revised.
California Division of Mines Bulletin 123,  Feb. 1943.

Arizona,
California (act of the California legislature of May 23, 1901),
Montana, Oregon
1.5 cubic feet of water per minute

Alfred H. Ricketts.
American Mining Law with Forms and Precedents. 4th ed. enlarged and revised.
California Division of Mines Bulletin 123,  Feb. 1943.

southern California (“regardless of the legal definition”),
Idaho, Nebraska, Nevada, New Mexico,
North Dakota, South Dakota, Utah
1.2 cubic feet of water per minute

Alfred H. Ricketts.
American Mining Law with Forms and Precedents. 4th ed. enlarged and revised.
California Division of Mines Bulletin 123, Feb. 1943.

Early Definitions

1" square aperture through a 2" plank with water 6" above the top of the aperture, 2,274 cubic feet in 24 hours,

which does not agree with Fay's definition of the miner's inch as a flow of 1.5 cu. ft per minute, which would be 2160 cubic feet in 24 hours. 

... the miner's inch is a flow of 1.5 cubic feet per minute through any aperture or orifice.

Albert H. Fay.
A Glossary of the Mining and Mineral Industries.
U. S. Bureau of Mines Bulletin 95, Washington, 1918.

 

The term Miner's Inch is more or less indefinite, for the reason that California water companies do not all use the same head above the centre of the aperture, and the inch varies from 1.36 to 1.73 cu. ft. per min., but the most common measurement is through an aperture 2 ins. high and whatever length is required, and through a plank 1¼ inches thick. The lower edge of the aperture should be 2 ins. above the bottom of the measuring-box, and the plank 5 ins. high above the aperture, thus making a 6 in. head above the centre of the stream. Each square inch of this opening represents a miner's inch, which is equal to a flow of 1½ cu. ft. per min.

William Kent.
The Mechanical Engineers' Pocket-Book. 9th edition.
New York: John Wiley & Sons, 1916.
Page 18.

A miner’s inch day was the quantity of water produced by a flow of 1 miner's inch for a period of one day.

resources

Commentary on the unit from a late 19th century author, and a drawing of the device often used, is provided here.

home| units index| search| to contact Sizes drawing of envelope| acknowledgements| help|

privacy

terms of use