RIVER MEANDERS ON THE MIDDLE ROUGE 763 



off, the flat character of the bottom caused the water to flow in a thin 

 broad stream, and that the meanders were caused or formed as the 

 narrower stream cut back from the dam. This is rendered probable 

 by the fact that near the dam, in so far as there are any inequahties of 

 surface, the water does not occupy the lowest land. This would tend 

 to show that inequality of surface was not the determining factor in 

 causing the meandering. The question naturally arises: What did 

 cause the stream to meander ? 



According to the U. S. contour map of the locahty, the average fall 

 of the stream per mile is about ten feet above the old pond and about 

 six feet below. If the stream had assumed a straight path, it would 

 have had a fall of over thirty feet to the mile in the floor of the old 

 pond. As a matter of fact, it, by its meandering course, reduces 

 the fall to about fifteen feet to the mile. These numbers are only 

 approximations; but can be verified by consulting the accompanying 

 map. Even this is more than the average fall per mile in the course of 

 the stream. This is what we should expect, as while in the old pond 

 the stream has graded its course, it is still cutting down to conform 

 to the grade of the stream as a whole, which it will reach in time. 



Considering the width of the flood plain, however, it will be seen 

 that it would be impossible for the stream to decrease its rate of fall 

 farther by meandering, as it already swings from side to side, cutting 

 into both boundary bluffs. In so far as the conditions permit, the 

 stream has apparently endeavored to conform to the general grade of 

 its course in its path across the floor of the old pond. This gives rise 

 to some very interesting questions. 



What does meandering mean ? Does it mean a response to sur- 

 face configuration ? Is it dependent upon the nature of the material 

 in which the river is cutting its course ? Does it bear any relation to 

 stream velocity ? Is it necessarily associated with the lower courses 

 of streams because of a decrease in velocity, or is it because of a 

 decrease in freedom to meander due to the width of the flood plain 

 caused by lateral cutting ? 



These meanders are not inherited, neither are they the result of 

 lateral cutting. Most of the work done by the river since the dam 

 gave way has been vertical cutting. The banks are vertical and 

 remain so on account of the fine, homogeneous clay of which they are 



