2 Sh ee eee ee 
STEADY FLOW OF WATER IN UNIFORM PIPES AND CHANNELS. 333 
Wrought-tron pipes. (Darcy) 
Pig. 4, 
fig 10 
nel (Triangular 
Wooden Chan: (rangle 
, tog ® : 
11. On the determination of k’ in the expression U* =k’ I.— 
Resuming equation (19) we have, on taking the logarithm of both 
Sides, and transposing. g; 
log k” = n log U—log /.... (21) 
hence log &” may be found for each observation made, by multiply- 
ing the logarithms of the velocities by the proper value of m, and 
subtracting the logarithm of the east The mean for each series 
. 
