Great Ice-Dams.— Taylor. 27 
westward from Findlay is generally about ten feet below the 
Maumee, but on the north side Mr. Gilbert reports it about 25 
feet below. It has been traced to the head of both outlet chan- 
nels.* 
When the ice-dam retreated to the Detroit-Euclid line no 
new outlet was opened, so that the same two ways of discharge 
continued to serve. On the thumb in Michigan the ice-front 
did not draw back far and the newly uncovered ground was a 
trifle higher than the Imlay channel. To the north, however, 
the thumb slopes gently downward and its crest was in a re- 
entrant angle of the receding ice-sheet. 
Referring to the Leipsic beach in Ohio, Mr. Leverett says: 
"The general appearance of this beach is much like that of 
the Van Wert, though it is on the whole somewhat stronger. 
Throughout much of its course it stands 6-8 feet above the 
plain north of it, and in places 15-20 feet."f This is precisely 
as would be expected, for this stage of the lake lasted during 
two halts of the receding dam. 
Lakes Whittlesey and Safi^hiazv. The two ice-dams which. 
retained this lake stood on the Port Huron and Gowanda mo- 
raines. As soon as the ice began to withdraw from the Detroit 
moiaine new points of overflow opened across the thumb 
farther north, but served only as temporary spillways. For the 
ice was retreating down hill and the place of overflow kept 
cer's "Maumee" in Michigan is the same as Gilbert's No. 2 and Win- 
chell's Leipsic ridge in Ohio. This beach passes into the head of the 
Imlay channel west of Port Huron and ends there. The name "Mau- 
mee," which Spencer applied to Gilbert's beach No. 2, supposing 
that beach to be No. i, is in fact now applied to No. i, as noted above. 
Observations show that neither the IMaumee nor the Leipsic beach 
extends to the Saginaw valley or to Chicago. 
*Until recently, the connection of the Leipsic beach with the Fort 
Wayne outlet seemed to the writer improbable, for Mr. Gilbert re- 
ported it to be on the average about 25 feet below the Maumee, (Ge- 
ology of Ohio, Vol. I, p. 552) at the same time giving the average depth 
of the head of the Fort Wayne outlet near New Haven, Ind., as only 
20 feet. (p. 550). But. Mr. Leverett recently called the writc-'s at- 
tention to the fact that on the south side of the valley, from Findlay 
V. cstward about to the state line, which is as far as he had traced it. 
this breach averages only about ten feet below the Maumee, thus 
bringing it up high enough for the supposed connection and putting 
it in accord with the conditions indicated by the Imlay channel, which 
is certainly too narrow to have carried the whole discharge of the lake. 
This relation seems to indicate that there was also at the same time a 
considerable discharge through the Fort Wayne channel. 
t.\m. Jour. Sci., April. 1S92, p. 293. 
