131 



, e being 



Hydraulic Investigations. 



13"2l 1-0563 x . , 1 



(1083 + . _ + __), an d b = ^-^-^^ 



&c/ • ■-'{ , .ds cc. c 



-j-, a«d^, V (M + f>«-*J or t= ^( fl + fla )- -> 



as before; and in either case the superficial velocity of a ri- 

 ver may be found, very nearly, by adding to the mean ve- 

 locity* v its square root, and the velocity at the bottom by 

 subtracting it. 



Talk of Coefficients, for English Inches, 



II. Of the Resistance occasioned by Flexure in Pipes or Rivers* 



Mr. Dubuat has made some experiments on the effect of 

 the flexure of a pipe in retarding the motion of the water 

 flowing through it; but they do not appear to be by any 

 means sufficient to authorise the conclusions which he has 

 drawn from them. He directs the squares of the sines of 

 the angles of flexure to be collected into one sum, which, 

 being multiplied by a certain constant coefficient, and by 

 the square of the velocity, is to show the height required for 

 overcoming the resistance. It is, however, easy to see, that 

 such a rule must be fundamentally erroneous, and its coin- 



I 2 cidence 



