Water Inch
Water Inch :
A traditional unit of water flow, supposed to equal the flow through a circular opening one inch in diameter, assuming the flow is caused only by gravity. However, this flow rate also depends on the pressure of the water above the opening. One estimate is 14 U.S. pints per minute or 2520 U.S. gallons per day [2] (this is equivalent to 6.624 liters per minute); this estimate assumes the water level is constantly 1/12 inch (1 line) above the top of the opening. Another is 500 cubic feet per day, which is much larger: 3740 U.S. gallons per day or about 9.832 liters per minute. The latter estimate may depend on a mid-nineteenth century British engineering definition which required the hole to be centered 1 inch and 1 line below the water surface, placing the top of the opening 7/12 inch (7 lines) below the water level. See also miner's inch
