196 EXAMPLES. 



Hence, if we wish to conduct a given quantity of water 

 through a pipe with as little loss of head as possible, we 

 must make the pipe as short and its diameter as large as 

 we can. If the diameter of one pipe is double that of 

 another, the friction in the former is -% of that in the 

 latter. 



COR. Putting 1 + = 1.505, and i = 0.0155, we 

 have, from (2) and (4) of Art. 104, 



h = (l.505 + /4) 0.0155v 2 , (7) 



and v = 8.025A / (8) 



V 1.505 



EXAMPLES. 



1. How many gallons of water would the pipe in the ex- 

 ample of Art. 105 deliver in 24 hours ? 



Here v = 5.8 and d = 6 inches ; we have, from (4), 



Q = 2936.86 x6 2 x 5.8 



= 613216 gallons in 24 hours. 



2. What must the head of water be, when a set of pipes 

 150 feet long and 5 inches in diameter is required to deliver 

 25 cubic feet of water per minute ? 



Here we have, from (5), 



OK 1 2* 



v = 1.2732 x ^ X -p- = 3.056 feet, 



and therefore (Art. 105, Sch.), / = .0243, which in (7) 

 gives 



(1 *iO v 1 2\ 

 1.505 + .0243 x -^--j .0155 x 3.056 2 



= (1.505 + 8.748) .0155 x 9.339 = 1.484 feet. 



