128 Notices of Memoirs—Old Floods in the Connecticut. 
the altered Highland rocks overlie the fossil-bearing series, and in 
another that they underlie them. By an unconscious selection of 
favourable sections, either of these two mutually destructive views 
could be supported by what a partisan would naturally claim to be 
an overwhelming mass of evidence. 
(To be continued.) 
WOTLG nS (Oi () Man VO ES. 
Tue Froop oF THE Connecticut River VALLEY FRoM THE MELTING 
OF THE QUATERNARY GuacrER. By James D. Dana. (Amer. 
Journ. Science, vol. xxiii. 1882.) 
HE title of this paper indicates its principal contents ; the author 
pictures the general condition of the Connecticut and its tribu- 
taries during the progress of the flood, he treats of the origin of the 
channel-way of the river, of its terraces, and the bearing of the facts 
on the retreat of the glacier. According to the process described 
the terrace-plains were formed during the rise of the waters. The 
following conclusions may be read with interest :— 
« At the time of maximum flood the ice was not lying along the 
center of the valley producing the river by its gradual melting, and 
retreating northward as the river elongated in that direction. The 
amount of water flowing off with a velocity of three or four or more 
miles an hour, making the great flood, was too vast to have been 
generated from a retreating body of ice in the valley. If, as Green- 
land facts authorize us to believe, sub-glacial rivers of large size and 
energy were a universal feature of the Glacial era, these streams 
must have entered on a career of real progress when melting began 
in earnest. As they enlarged, the icy tunnels they had hitherto 
occupied would have become widened, and the sub-glacial chambers 
have extended themselves in all directions, undermining the heavy 
glacier. And as rapidly as this removal from below went on, the 
deposition of the materials of the ground moraine—the stones, 
gravel, earth and clay—long before initiated—would have gone for- 
ward, covering with till the glacier-buried land. But subsequently, 
when the rising streams had volume enough to make the lower range 
of terraces, along the valleys, the roofs of the tunnels were probably, 
for the most part, gone. The ice still lay over the land, covering 
deeply the hills and mountains, but the wide channel-ways were 
open to the day. Evidence of this is afforded by the fact that these 
lower terraces, like the higher, are free, with rare exceptions, from 
deposits or droppings of till or of bowlders, such as would have come 
from an overhanging glacier. But outside of the terrace plains, up 
the hill-slopes, wherever the ice still remained in force, the till may 
have continued to fall, adding later to earlier till.” 
At the time of maximum flood the ice melted might have reached 
the amount of a cubic mile per day. 
