38 Charles Whittlesey of Cleveland, on Natural Terraces, Gee 
ata beach, for the surface of the water would be level. If we 
suppose them to have been formed in that manner, when the 
water stood at the base of a ridge, the rivers must have ‘discharged é 
at the same level. Here should, on that ind be found del- 
tas, and evidence of bays or lagoons. The s having settled 
away, at the present period the streams aiachadee at a lower level, 
their channels being worn deeper and larger, ree through the 
ridges and terraces that lie between the present and the ancient 
level. If the ancient mouth was at a point different from that- 
where the present channel cuts a nidge, it should be visible in the 
present form of the ridge. If it was at the same point, there 
should be marks of such action as always accompanies the meet- 
ing of running currents with dead water. But our streams a 
pear to cut the ridges as though they were barriers preéxisting, 
and — through by the current. 
races composed of the rocks or other general deposits of a 
ccunaa appear to be much stronger proof of ancient shores than 
limited sand ridges. When we rise above 240 feet from Lake 
Erie, the well defined terraces disappear; and from that line to 
6v0 to 650 feet, the general elevation of the table land in North- 
eastern Ohio, the surface presents a confused arrangement of heavy 
drift, covering the rocks at various depths, in long massive knolls, 
without ranges or parallelism. 'Towards the west, the summits 
of the lake streams are lower, and the present surface of North- 
western Ohio and Northern Indiana, of Illinois, Michigan, New | 
York and Canada West, with much of Wisconsin and Jowa, 
would be submerged by a sea ring 250 feat above Lake Erie, or 
815 above the ocean. 
The Wabash and Maumee summit, at Fort Wayne, Indiana, is 
246 feet above Lake Erie. The summit between the waters 0 
Saginaw Bay, and of Lake Michigan, . 108 ft.above L. Ere. — 
Summit between Pishtaka and Rock River pin: 918 « ‘i ; 
in Illinois, : : 
Lake Winnebago 1 is a 
Summit between ’ Lake Ontario and Lake 197. « = 
Simcoe, Canada, 
Mouth ne nt Peter’s River, Fort Snelling, 
Mine 179 [7 74 
Missouri Rives ait Fort ‘Leavenworth, went isl « ds 
line of state of Missouri, 
If, therefore, the relative level of the land was the same as now, 
= when the diluvial sea existed at high levels, its extent must have 
€ very sek, at the supposed stage of 250 feet above Lake 
i 
one: 
rie. At this or any other supposable stage, if it remained sta- 
onary long enough to form cliffs and banks at one place, it 
would produce the same effects, in kind if not in degree, at an- 
poh and we should be able to trace beaches or shores over all 
