196 
The Ohio Naturalist. 
[Voi.yin, No. i, 
It was noticed, as above stated, that the doubling of the 
volume more than doubled the power of the stream. If the 
volume could have been doubled without increasing the velocitv, 
undoubtedly the power would have been little more than 
doubled, but this is probably impossible; and since increasing 
velocity so greatly augments power, the marked increase is thus 
explained. 
To test the influence of changes in slope, the steepness was 
increased and decreased temporarily under various conditions. 
The results may be summarized as follows: During the earlv 
part of the experiment when the stream was constantly loaded 
to its maximum capacity, decreasing the steepness checked the 
velocitv and power of the stream from the loading point to its 
mouth, and hence reduced the rate of deposition because the 
stream could not start as much waste as formerly, when its power 
was greater, and manifestly could not drop as much either. 
Under the same loaded conditions with abundance of waste to be 
picked up at the source, steepening the slope increased deposition 
instead of initiating erosion because the stream was able to pick 
up more waste at the start and hence had more to drop along the 
valley. These results are really not anomalous, but, when the 
problem is thought out, quite expectable. No quantitative 
tests, were made but the general results as here stated were so 
apparent that we believe the facts are exactly as stated above. 
When the stream was degrading during the latter part of the 
experiment, a slight increase in slope increased the rate of 
degradation and a similar decrease in steepness checked erosion, 
while more reduction in slope stopped erosion almost completely. 
Inasmuch as such changes in slope do not enter into the 
ordinary field problems of streams we may consider the effects 
of changes in volume of water and quantity of waste in their 
general application without considering changes of slope. The 
experiment was somewhat abnormal to nature in another 
respect, for in nature waste is not usually fed into a stream, 
absolutely as fast as the stream will pick it up regardless of 
variations in the stream’s power. In nature, supply of rock 
waste varies with the volume of water. 
Resulting land forms. -The forms resulting from a river’s 
aggrading and subsequently degrading its course are mainly of 
an ephemeral type. To begin with a constructional plain is 
formed occupying the valley filled. This plain is composed 
of loose, more or less systematically stratified materials which, 
as a rule, do not have time to become much consolidated 
or cemented before the stream changes its habit and proceeds to 
send the waste, temporarily rested along the valley, on its 
journey to the sea. Terraces are thus carved with their level, 
often crescentic top plains and their steep, serrate, or cuspate, 
