A further modification of the Reynolds formula, proposed by Thrupp, 

 is given by 



, C n v n I d 



h = where m = -. 



m* 4 



The following are values of 6', x, and n for pipes of various materials, 



and for pipes of between 2 and 15 inches diameter the formula gives 

 good results. For wrought iron pipes of less than 2 inches diameter a 

 correction should be applied by writing 



x 4- a V 1 for x, where a = '0324 ; b = '07. 



m 



Tutton, adopting the Thrupp formula, as a result of an examination of 

 approximately 1,000 experiments by various observers obtained the 

 following mean values for n, C, and x. 



Society of Engineers, 1887. 



