HILLSIDE OSAES OR ESKEES. 365 



The region is hilly. I have noted about fifty of these eskers, and doubtless 

 there are many more. 



At their northern extremities a large proportion of the hillside systems 

 begin at the southern brow of broad flattish-topped hills 100 to 400 feet 

 high; others begin at various distances down the southern slopes of the hills. 

 The hillsides fall southward or southeastward. I have discovered no ridges 

 of this class on the northern slopes of hills, nor developed on the tops of 

 the hills and plateaus. These eskers all end at the south in the valleys 

 lying at the southern bases of the hills in which they are found. All expand 

 somewhat at their southern extremities, some into a larger ridge, some into 

 a small plexus of reticulated ridges inclosing basins, some into a fan-shaped 

 or oval delta. Beyond the limits of this terminal enlargement I have not 

 been able to trace glacial sediments, though in some cases the terminal 

 deltas merge into the alluvium of the valleys in which they lie in such a 

 way as to indicate that the alluvium is kame or overwash matter with 

 respect to the ice and the glacial stream. These ridges meander soinewhat, 

 yet on the average diverge but little from the lines of steepest slope of the 

 land surface. Owing to the outlook of the hills, this direction is nearly the 

 same as that of ice flow, and also must be about the same as the direction 

 of the slope of the ice surface in late glacial time. The hillside eskers vary 

 in height from 5 feet or less to 20 feet, and in length from a short eighth of 

 a mile to nearly 2 miles. The sediment composing- them is usually gravel 

 and sand, but in some cases there are cobbles, bowlderets, and even a few 

 bowlders, all distinctly but not very much worn and rounded by water. 



The position of the terminal enlargement and delta, their situations 

 on the southern slopes of hills, and many other considerations prove con- 

 clusively that the flow of the streams that deposited the hillside systems 

 was southward. If on the slopes of moderately steep hills the velocity of 

 the waters that deposited the gravels was so gentle as to permit the 

 deposition of sediment, such as sand and gi-avel, we may be certain that 

 the conditions would be still more favorable to deposition on the northern 

 slopes and the tops of the hills. On the contrary, no water sediments are 

 found there, nothing but the usual till, and no ravines of erosion. If the 

 streams which deposited these kames were subglacial in that part of their 

 courses lying nortn of the kames, they there had a very gentle current, not 

 capable of eroding the till or transporting sediments up the hills. 



