198 



has been shifting its course during the past few centuries. The dotted 

 hues indicate the location of ridges, which when carefully traced are 

 found to mask one or the other of the banks of the more ancient stream. 



I will I'eturn to this after detailing some of the operations of the 

 agencies which I have observed during the past quarter of a century. 



At z, Fig. A (enlarged section, Fig. C), is a small tableland (t), which 

 twenty to twenty-five years ago was broader and extended upstream five 

 to seven rods further than it now does. In half a century more, at the 

 present rate of erosion, the part of the tableland still remaining will all 

 have disappeared, and what is now a well defined ridge will have become 

 a bluff. Both the ridge and the tableland are covered with forest trees, 

 while the bluff for a mile up the stream, and from the point of contact (u) 

 of river and ridge, is barren, indicating constant and rapid weathering, 

 and consequently a gradual northward movement of the stream bed. 

 I shall return to this again after giving fuller observations of similar 

 changes at the bend y. Fig. A. 



This bend is best studied in Fig. B. More than twenty years ago I 

 was familiar with the bar, n', lying under but upstream from the syca- 

 more tree, v, which still stands. Then the bar, n' (see n, Fig. D), was 

 the only one, and formed the river bank. It was of pure, washed sand 

 and had no vegetation whatever growing upon it. It now has willow 

 and sycamore trees five or six inches in diameter. Now, also, there is 

 another bar (w' in Fig. B and w in Fig. D), which is the one bordering 

 the river, of pure, washed sand and without vegetation. 



These facts stimulated further investigation and furnished the key to 

 deeper secrets. I examined the topography farther east and found a 

 considerable elevation about forty feet wide (m' in Fig. B and m in 

 Fig. D), and succeeded by a lowland; then, again, another rise, 1 (1'), 

 extending eastward for two hundred and fifty feet, and in turn succeeded 

 by a sink, better marked than any of the others (see k in Fig. D and k', 

 Fig. A). Both these bear evidence of being former bars, and their relative 

 ages are evidenced by the trees, which I have tried to indicate in my 

 drawings, by trees and stump. Those trees which have grown upon m 

 (m') are not larger than fifteen inches in diameter, while those upon 1 (1') 

 were large forest trees, many three and four feet in diameter. This 

 last is all cleared of its timber now and is a well cultivated field. In 

 Fig. A, n", m", 1", and k' do not represent the correct relative distances, 

 only relative position. 



