2O CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



In tabular form the figures, taken from the Danbury and 

 New Milford atlas sheets and from reports of R. E. Dakin, are 

 as follows : 



Miles Fall in feet per mile 



Source to Sherman 4 177-5 



Sherman to Wood Creek 8 6.25 



Wood Creek to Jerusalem 4.5 3.8 



Jerusalem to mouth 2.5 69.2 



Near Jerusalem, where Rocky River makes its sudden change 

 in grade, there is an abrupt change in the form of the valley 

 from broad and flat-bottomed to narrow and V-shaped. The 

 profile of Rocky River is thus seen to be sharply contrasted with 

 that of a normal stream, which is characterised throughout its 

 course by a decreasing slope. 



PREGLACIAL COURSE 



The present profile of Rocky River and the singular manner 

 in which the lower course of the river is doubled back on the 

 upper course are believed to represent changes wrought by 

 glaciation. Before the advent of the glacier, Rocky River prob- 

 ably flowed southward through the " Neversink-Danbury Valley," 

 to be described later, and joined the Still at Danbury, as shown 

 in fig. 4. The profile of the stream at this stage in its history 

 is shown in fig. 3, B. 



At Sherman a low col separates Rocky River basin from that 

 of the small northward flowing stream which enters the Housa- 

 tonic about a mile below Gaylordsville. Streams by headward 

 erosion at both ends of the belt of limestone and schist on which 

 they are situated have reduced this divide to an almost imper- 

 ceptible swell. The rock outcrops in the channel show that the 

 glacier did not produce any change in the divide by damming, 

 though it may have lowered it by scouring. Assume that at one 

 time a divide also existed on the eastern fork of Rocky River, for 

 example near Jerusalem. According to this hypothesis there 

 was, north of this latter divide, a short northward flowing branch 

 of the Housatonic located on a belt of weak rock, similar to the 



