* 
190 J. D. Dana—The Flood of the Connecticut River Valley 
. Mean slope of the river in case the land ie ocean: had their 
an sane as to level.—Supposing the land and ocean in 
measured along the valley (taking no note of the on in the 
river) between localities, on a scale of a twelfth of an inch to 14 
miles. We thus find for the slope: 
Distances Slope 
in miles, per mile. 
Haverhill (655 ft. pon age dh to Windsor (520), .-..-.-.-. 41 3°3 feet 
Windsor (520) to South Vernon, Vt. ‘a 3 BS a cee nN oe 49 2°5 
South Vernon (396) ap Springfield, MRE C240 44. 3° 
Springfield (240) to the Middletow n Narrows (LOD) er 38 1-2 
Narrows (195) to Long [sland Sound, .-.... _._..-___.. 26 7:4. 
caaeon Ssasid! to the Middletown Narrow s (195), . ‘ 172 2°71 
m (396) to the Middletown acives (195), - S83 82 2°5 
Haver t b the Sound, e 198 3°3 
outh Vernon to the So und, yee kent ah See A eee Eee aR N 108 3°6 
From the above 5 ey peeks that, except for the dam at the 
Middletown Narrows, the mean slope from Haverhill to the 
Haverhill to Windsor. But, owing to the dam, the mean slope 
to Middletown is but 2°7 feet, eile below the Narrows it is 7-4 
feet per mile. 
B. Mean velocity.—To obtain the velocity, we have the 
data above hss is for the mean width, depth and aispe of 
the flooded riv 
Another Sadek required is the amount of resistance from 
bends and obstructions in the stream. It is fortunate for the 
calculations that the ees valley follows a remarkably 
straight north-and-south ¢ With the water raised 20 
a rapid stream. On the map of the river and valley between 
Wells River and Bellows Falls, figure 4, Plate 2, the band covered 
by the deposits, indicated by the dotted outline, shows that the 
waters made nearly a straight stream. The map is somewhat 
short of the truth, since the upper terraces are absent in parts 
of the valley and particularly so for the narrower part along 
from Ely to Piermont. Only a map that gave on each side of 
the valley the eras line corresponding to the he ight of maxi- 
mum flood, and also the limits of the channel-way as marked 
by the inner limits of the highest terraces, would show fully 
the degree of straightness. 
