CONVENIENT EQUIVALENTS 69 



1 second-foot equals 40 California miner's inches (Law March 23, 1901). 



1 second-foot equals 38.4 Colorado miner's inches. 



1 second-foot equals 40 Arizona miner's inches. 



1 second-foot equals 7.48 United States gallons per second; equals 448.8 



gallons per minute; equals 646,317 gallons for one day. 

 1 second-foot for one year covers 1 square mile 1.131 feet or 13.572 inches 



deep. 



1 second-foot for one year equals 31,536,000 cubic feet. 

 1 second-foot for one day equals 86,400 cubic feet. 

 1 second-foot equals about 1 acre-inch per hour. 

 1,000,000,000 (1 United States billion) cubic feet equals 11,570 second-feet 



for one day. 



1,000,000,000 cubic feet equals 414 second-feet for one 28-day month. 

 1,000,000,000 cubic feet equals 399 second-feet for one 29-day month. 

 1,000,000,000 cubic feet equals 386 second-feet for one 30-day month. 

 1,000,000,000 cubic feet equals 373 second-feet for one 31-day month. 

 100 California miner's inches equals 18.7 United States gallons per second. 

 100 California miner's inches for one day equals 4.96 acre-feet. 

 100 Colorado miner's inches equals 2.60 second-feet. 

 100 Colorado miner's inches equals 19.5 United States gallons per second. 

 100 Colorado miner's inches for one day equals 5.17 acre-feet. 

 100 United States gallons per minute equals 0.223 second-foot. 

 100 United States gallons per minute for one day equals 0.442 acre-foot. 

 1,000,000 United States gallons per day equals 1.55 second-feet. 

 1,000,000 United States gallons equals 3.07 acre-feet. 

 1,000,000 cubic feet equals 22.95 acre-feet. 

 1 acre-foot equals 325,850 gallons. 



1 inch deep on 1 square mile equals 2,323,200 cubic feet. 

 1 inch deep on 1 square mile equals 0.0737 second-foot per year. 

 1 foot equals 0.3048 meter. 

 1 mile equals 1 .60935 kilometers. 

 1 mile equals 5,280 feet. 

 1 acre equals 0.4047 hectare. 

 1 acre equals 43,560 square feet. 

 1 acre equals 209 feet square, nearly. 

 1 square mile equals 2.59 square kilometers. 

 1 cubic foot equals 0.0283 cubic meter. 

 1 cubic foot of water weighs 62.4 pounds approx. 

 1 cubic meter per minute equals 0.5886 second-foot. 

 1 horse-power equals 550 foot-pounds per second. 

 1 horse-power equals 76 kilogram-meters per second. 

 1 horse-power equals 746 watts. 

 1 horse-power equals 1 second-foot falling 8.80 feet. 

 1$ horse-power equals about 1 kilowatt. 



sec.-ft.X fall in feet 

 To calculate water power qujckly: =-net horse-power on 



water wheel realizing 80 per cent of theoretical power, 



