J.D, Dana—The overflows of the flooded Connecticut. 507 
verflow from the region of Northampton, by the west side of 
og Tom, to Westfield, to join the flow down the Farmington Val- 
ley.—The obstacle here was the divide north of Westfield. 
The upper terrace of the Northampton region is one of the 
best defined terrace-plains of the Connecticut valley. It is 
only two miles west of Northampton, and is known as the 
Florence plain, part of it being the site of a village of that 
name. Its height above mean sea-level, according to the sur- 
vey for supplying the city with water, as I am informed by 
Mr. E. C. Davis, Civil Engineer, is 260 to 285 feet. The terrace 
which Prof, Hitchcock gives as the highest in northern North- 
ampton occurs also just west of the city, though with the sur- 
face rising westward; its height he gives as 97 feet above low 
water, and 202 above tide level; and it is therefore 60 feet 
below the level of the Florence plain. 
The Florence-plain level, 260-265 feet, is evidently a north- 
ward continuation of the upper Springfield level, that of 240- 
245 feet. There is hence a difference of level of 20 feet in a 
distance of 16 miles. But if the land were depressed, with 
the depression increasing northward at the rate of a foot a 
mile, the pitch would have been slight. How far the narrows 
between Holyoke and Tom affected the height of flood-level 
above and below, I have not investigated. 
From the height of the upper terrace-plain at Northampton, 
we know that the flood-height there was not below 265 feet; 
and probably it was 10 or 15 feet above this, as Hitchcock men- 
tions a terrace of 289 ie near Hadley. What then was the 
level of the Westfield divide? 
This divide at its pete part, where it was gps by the 
armington canal, has a height of but 241 feet above mean 
sea- level, which is more than 20 feet below thee ae level at 
Northampton. We have good evidence, therefore, that the over- 
flow took place, and that the stratified drift of the divide owes 
to it its deposition. High terraces exist eng the sides of the 
valley between the divide and Northampt 
Passing the divide the waters join foe of the flooded 
Westfield River; and if so, they became part of the overflow 
which descended by the Farmington, at eae and Mill 
River yarleys to New Haven and the Soun 
Conclusions. —(1.) The Connecticut ne the Glacial flood 
was at its ta height had a ‘depth of 150 feet, or more, all the way 
from Middletown to Turner’s Falls at Springfield—and to an un- 
determined distance beyond; and from Hartford to Turner's 
Falls it averaged fifteen ‘miles in width. It was a great stream, 
by numerous headlong torrents from either side; and, at 
the same time, feeding other streams from its surplus waters, 
Its depth and extent was in spite of great losses from overflows 
eys. 
‘Into other valle 
