Miscellaneous. 327 



than three times the head, A M. The formula given is 

 for a weir without end contractions, as Fig. I ; that is, 

 the width of flume leading to weir must be the same 

 width as the overflow and not contracted, as in Fig. 3. 

 After getting Q, or cubic feet of water flowing per 

 second, it is easily reduced to gallons flowing per min- 

 ute, hour or day. As there are 1,728 cubic inches in a 

 cubic foot and 231 cubic inches in a gallon, a cubic foot 

 of water contains 1,728 inches divided by 231 inches, 

 or 7.4805194 gallons, or nearly 7^ gallons. The flow 

 is generally calculated for the number of gallons per 

 day of twenty-four hours." 



There must be other mathematical dunces, and so I 

 wrote Air. Osterhout that his formula was no doubt 

 correct, but was not in the shape to be "understanded 

 by the people" ; also that fishculturists reckoned the 

 flow per hour, and that if he would kindly translate this 

 formula into a flow per hour per foot width of dam it 

 would just hit the mark. 



Then he got down to the fishcultural level and wrote : 



"CoL. FRED MATHER : Your mathematical difficulties 

 are appreciated and I enclose you a table, showing gal- 

 lons per hour discharged by a one-foot weir for depths 

 from o to i foot. I have also put in the decimal of a 

 foot corresponding to each half inch. For any weir 

 other than one foot in length multiply the number of 

 gallons opposite any head by length of weir. 



"Example. How many gallons per hour will flow- 

 over a 4-foot weir, with a head of 3^ inches? 14,128% 

 4=56,512 gallons. If the weir is 4 feet 5 inches long, 

 the 14,128 for a head of 3^ inches must be multiplied by 



