2o6 



POPULAR SCIENCE MONTHLY. 



Fig. 11. A Glacial Boulder in the Keene Valley. 



covered, open and swampy area to the southwest and directly in the 

 line of its previous courses. It is apparently a case of reversed drain- 

 age. After a somewhat sinuous easterly course of eight or ten miles, 

 the Hudson turns again abruptly south, receiving at the same time 

 the Boreas Kiver, which comes in from the north with the waters of 

 a broad, open region much masked by drift and filled with swamps 

 and lakes. It would seem as if the Hudson had jumped thus from 

 one older drainage line to another. The Hudson next flows due south 

 for four or five miles, then turns once more eastward, for eight miles, 

 then south and southeast until it again turns eastward, northward and 

 finally eastward with marked meanders across the great sandy plain 

 near Glens Falls. Finally at Sandy Hill it swings around once more 

 to the south and takes its nearly uniform course for the sea. 



The Sacondaga Biver has also this same peculiar rectangular bend- 

 ing from north and south to east and west courses, and with a most 

 peculiar turn parallel in all respects to the bend of the Hudson, it 

 swings into the latter some miles above Glens Falls. 



These bendings are in large part to be explained by the old series 



