370 S. H. BARRACLOUGH AND T. P. STRICKLAND. 
be the velocity and J the slope we have 
Vaki* 
where & is a constant. The degree of accuracy with which this 
simple expression represents the experimental results renders 
it unnecessary to enquire whether any other form of expression 
could not be used for the same purpose. 
Fig. 3. 
Curves necaeaasia . 2) ron to Series iB 
Series IT. 
Cue ached ma nd G” wow ws the aS obtained by applying the 
formula of Kutter and Ganguillet to Series II 
Log of Slope. 
3°70 3:90 2°10 2°30 2-50 270 2-90 1:10 
Log of Velocity (U) 
20 40 60 80 100 120 140 160 
Vel. cm. per sec. 
