96 G. K. Gilbert—The Colorado Plateau Province. 
The second element is the addition which the detritus makes 
to the friction of the stream. The coefficient of friction of the 
sumed in the friction of the detritus on the stream bed, accom- 
plishes as part of its work the mechanical corrasion of the bed.] 
tact varies directly as the square root of the quantity of water. 
Hence, celeris paribus, the friction of a stream on its bed, is pro 
portioned to the square root of the quantity of water. But, as 
e : , 
ly to the quantity of water. And also, the total energy 8 _ 
_ It follows, as a corrollary, that the running water which cat- 
ries the debris of a district, loses power by subdivision toward 
the full load which it is competent to carry. ee. 
t Is noteworthy also, that the obstruction which vegetation — 
eee to transportation, is especially effective in that it is 8p* 
P imal so 
t. 
A stream which can ics a debris of a given size, may be : 
said to be competent to such debris. Since the maximum party 
cles which streams are able to 
ity. Velocity, in turn, depends on declivity and volume, an@ 
(inversely) on load 
In brief, the capacity of a stream f ion i tet 
: or transportation is grea 
for fine debris than for coarse, ay 
