402 
Frank Carney 
V ertical Range. The gradient of an esker-forming stream 
probably is represented by the vertical range of the esker. In 
the following data the figures enclosed in parentheses represent 
the gradient in feet per mile of the esker stream: The range in 
altitude of esker No. i is lOO feet (i6o feet); of No. 2, 140 feet 
(82 feet); of No. 3, 80 feet (80 feet); of No. 4, if we consider only 
the unbroken segment, 15 feet (60 feet), but considering the 
scattered segments of the possible former esker the gradient is 
much sharper, as it trends eastward down the slope; of No. 5, 100 
feet (100 feet); of No. 6, 160 feet (320 feet); of No. 7, 70 feet (263 
feet); of No. 8 the gradient is broken since it crosses in its length 
of four and one-half or five miles, one marked valley and one valley 
of lesser development. The northern segment of this esker drops 
about 200 feet. Even this distance, however, is broken by the 
H orixorilaV Scale 2.2^"’= Imil^ 
Vertical Scale 20jeet. 
I I I i_ I __j -I- I I I — ~i — I — 4 — -j — -j — — i— — • — — • — • — L — 
Fig. 19. A profile showing the broken gradient of Esker No. 8. 
lesser valley just alluded to. The portion south of Dry Run 
rises about 120 feet. Fig. 19 plots the grade of this esker stream. ; 
The vertical range of esker No. 9 is about 30 feet (46 feet). 
From these figures, and the description of the eskers given in 
the preceding sections, it is apparent that streams of sharp grad- ; 
ient did not develop the highest esker ridges. The low eskers as . 
well as the ridges having low lateral slopes have the higher range \ 
in altitude. No. 7, however, appears to be an exception, but as 
already explained, the lower course of this esker has probably ( 
been so altered by outwash material and ice-front streams that the 
remnant represents but a fraction of the original development, 1 
and this remaining portion is the upstream end which has the i! 
sharpest gradient; the hypothecated removed segment had a lower 
gradient. On the other hand, eskers Nos. 4 and 9 have both a 
II I m r 
