y i ne f i 
428 G. K. Gilbert—The Deflection of Streams. 
processes involved. In the celebrated discussion in the French 
Academy of Science, it was computed by Bertrand that a river 
flowing in lat. 45° with a velocity of three meters per sec- 
ond exerts a pressure on its right bank of ;z4,, of its weight, 
and he regarded this pressure as too small for consideration. 
It has been pointed out by Henry Buff that the deflecting 
force, by combining with gravitation, gives the stream’s surface 
a slight inclination toward the left bank, thereby increasing the 
depth of water near the right bank, and consequently increast 
jing the velocity of the current at the right. ‘To this incremen- 
of velocity he ascribed a certain erosive effect, but regarded it 
as less than that assiznable to wind-waves on the same water- | 
nel, centrifugal force is developed. This centrifugal foree is 
velocity from the center of the channel toward the outer bank- . 
