For the sake of comparison, the values of /, x, and n, in the formula 



f I v n 



h = , x , as obtained by Unwin, Thrupp, and Tutton are given in the 

 cL 



following table. 



VALUES OF /, a>, AND n IN FORMULA h = *?* 



While these exponential formulae are more complicated than the old 

 formula of the De Chezy type, the increased accuracy rendered possible 

 by their use more than counterbalances any inconvenience in handling. 

 With the exception of the Kutter formula, which is exceedingly cumbrous 

 to handle without the aid of specially prepared tables, this inconvenience 

 is indeed more apparent than real since the formulae are in a form suit- 

 able for logarithmic or slide-rule calculation. 



