560 DE fOOLIVALVOLAGE OLOGY: 
probably 367 feet; at Caldwell, 385 to 390 feet; at Haledon it is 
405 feet. 
These figures show that the shore-line rises from 345 feet to 
412 feet from the southern to the northern end of the lake. The 
shore-lines, however, do not rise most rapidly in the direction of 
the longer axis of the lake, from southwest to northeast, but 
rather from south to north. Calculated in this direction, the rise 
is 67 feet in 25 miles, giving a gradient of two and two-thirds 
feet per mile. This rise northward is by no means regular. 
Within short distances, the gradient varies from nearly four feet 
per mile to less than one foot. In one or two instances, notably 
along the subaqueous overwash plain, the shore-line, after making 
all possible allowances, seems to be slightly lower than at points 
further south and southwest. The differential northward eleva-. 
tion of the lake basin, following the withdrawal of the ice, did 
not proceed with aconstant gradient. It was rather of the nature 
of an irregular warping and incipient buckling, with the greatest 
rise to the northward. 
The deformation of the shore-lines occurred after the lake was 
drained, rather than during different stages of the lake. This is 
shown by the fact that the Upper Preakness shore-line is every- 
where about 70 feet below the Montville level, whereas, if any 
deformation had occurred in the interval between these two 
stages, their shore-lines would not be essentially parallel. 
Roxuin D. SALISBURY, 
Henry B. KUMMEL. 
