9 
The index n begins at the value 2°83, increases with in 
creasing values of p, then decreases to a minimum, and finally 
increases again to a limiting value of 2°83; the position of 
the minimum index is not the place where the wave power is 
a maximum proportion (dp/dV=0) but at some velocity 
) VAL 2 3 4 
I 
f £09 V - 2 
greater than this value. Since the equivalent index n is 
given by d (log E)/d (log V), its changes may be exhibited by 
graphing log E upon a base log V; the slope of this curve 
gives the corresponding value of n. This has been done for 
the ship under discussion, and the result is shown in Fig. 3. 
67 
