— The Retreat of the Glacier. 369 
Glacial flood. This point is further exhibited in the following 
table, in which the monthly discharge of the Connecticut at 
Hartiord, for the years 1872 to 1877, is given from General 
Ellis’s Reports; and also the rainfall (snow. included) for the 
same years at Lunenburg, Vermont, two miles west of the Con- 
necticut, in lat. 44° 28’ N., long. 71° 44’ at a height of 
1124 feet above thes oe Hanover r, New Hampshire, —on the 
east bank of the river, in lat. 48° 42’ N., long. 72° 17’ W., ata 
height of 530 feet above the sea; and at Amherst, Massicho- 
setts, in lat, 42° 22’ N., long. 72° 84’ W., at a height of 267 
feet above the sea; the first, from tables kept hy Dr. H. Cut- 
ting of Lunenburg; the second, from the Dartmouth Observa- 
tory at Hanover (received from Prof. R. etcher); and the 
that the floods are not the immediate voids of great rains, and 
this 1 = “plain from mere inspection. in the Glacial era, the 
l water by soil-absorption was ake its minimum, by grow- 
ing veoeution almost null, and by chemical processes of oxida- 
tion and hydrationt se small, while ice to melt and melting 
and Base ground to flow over were essentially indefinite in 
exten 
re ‘allowance. shereiore, for the loss from evaporation and 
other causes, of 20 to 25 per cent, during the glacier-melting, 
cannot be far from right. Taking the mean of these numbers, 
per day, phe the latter to 0°9538. 
(6.) Disappearance of the Ice.—If the loss of ice by melting 
were 46071 cubic mules per year, and this amount continued to 
be the loss uninterruptedly, 8,215 cubic miles of ice would 
have been carried off in about 18 years; and if the annual 
*Gue marked exception occurred in August, Faget when the waters of the river 
tation at that time was enormous, havin n in that August 12° et nches at 
agp sgl and ph inches at Wallingford, Cotieisotlonte (B. F. Harrison, 
in ourn., xxi, 497, 
The loss by hydration here alluded to is in part that sate in —e the clay 
well the 
of the glacier discharge which is abundant in rarest e pro- 
duets—-bowlder-clay——of the Glacial era. Such clay has see aac by the = 
Fs sapere the feldspar which en _dicier-movernents — up, and w 
13 per cent or so 0 The decomposition is a remark 
pur contain 
fa oe ‘Dut it i s possible that. the decomposition of ‘the ne of the glacier may 
have made carbonie acid to promote 
