328 Modern Fishculture in Fresh and Salt Water. 



4.4167, the decimal .4167 being equivalent to 5 inches, 

 which is shown in the first column." 



Now that my engineering friend had got down to 

 the water level of the fishculturist, there was nothing to 

 do but to give his latest formula, and here you have it 

 in his own words : 



FRANCIS' FORMULA: 



Discharge in cubic feet per second = 3.33 X length of overfall in feet X 

 I/cube of head in feet. 



Discharge in gallons per hour = 3.33 Xby length of overfall in feet X 

 1 7 cube of head in feet X 7.4805 X3,600. 



7.4805 = number of gallons in one cubic foot of water or very nearly iy$. 

 number of seconds per hour. 



Discharge in gallons per hour of a ireir one foot long without end con- 

 tractions for depth from to one foot. 



