338 M. JEFFERSON LATERAL EROSION ON MICHIGAN RIVERS 



The average length of a scaur on the right valley bluff is 73 paces, on 

 the left 47. On the right there are, on an average, 3 scaurs to a mile ; 

 on the left, 2.4. Here is a reasonable persistence in behavior. However 

 we look at it, more work is being done on the right bank than on the left. 

 The number of scaurs is greater, the length of an average scaur is greater, 

 and the total amount of scaur is greater. The figures concerning the 



Scaurs on the Lower Rouge 



Course. ' 



Distance, 

 miles. 



Paces of scaur. 



Paces of 

 flood-i^lain. 



Percentages 



of bluff in 



scaur. 



Percentages 



of scaur on 



the right. 



Right. 



Left. 



Upper course. . . 

 Middle course . . 

 Middle course . . 

 Lower course. . . 



3.3 

 2.6 

 4.1 

 3.3 



469 

 653 



978 

 1,082 



140 

 357 

 591 

 137 



5,601 



4,126 

 6,406 

 5,810 



5 

 12 

 12 

 101 



77 

 64 

 62 

 89 





13.3 



3,182 



1,225 



21,943 



10 



72 



two stretches of middle course have been published in Science. The 

 measures on the lower course are due to the courtesy of Mr Isaiah Bow- 

 man, of Yale University, and Mr Barrel H. Davis, of the Central High 

 School, Detroit, assisted in obtaining the figures for the upper course. 



Middle Eouge 



Near Dearborn the Eouge is 30 to 50 feet wide, and has cut its bed 

 about 8 feet below the flood-plain, which in turn is 16 feet below the 



Eeach. 



Paces in scaur. 



Distance, 



miles. 



Percentages 



of bluff in 



scaur. 



Percentages 



of scaur on 



the right. 



Right. 



Left. 



Lower reach 



197 



735 

 76 



140 



49 



110 



6 

 6 



1 

 3 



1 



59 



Middle reach 



94 



Upper reach 



41 









1,008 



299 



16-J 



2 



77 



country about. The river here is muddy as usual, but after passing the 

 junction with the ISTorth branch the bottom can be seen, after heavy rains 

 of the previous week. This branch has water as clear as the Huron. 

 Generally speaking, the bluffs for the first 5 miles were wooded, and 

 scaurs were rarely observed, only 2 per cent of the wliole length of bluff, 

 which may have something to do with the clearness of the water. Here, 



