The number of cubic yards of gravel that can be broken down and sent through the sluice by 1 miner's inch of water for 24 h. It depends upon the height of the bank, the character of the gravel and the bedrock, the grade of the bedrock, the type of sluice, and the pressure of the water. In well-rounded gravel without large stones, the duty of the miner's inch is from 4.5 to 6 yd₃(3.3 to 4.6 m₃) of gravel for 24 h. Under less favorable conditions, the duty may range from 2.8 to 4.6 yd₃(2.1 to 3.5 m₃) for 24 h.