Art. I.] 
Fowke, Pre-Glacial Drainage near Cincinnati 
7 
If, however, the col at (C) was worn down in time for the 
water above it to escape through (F), then a fifth lake covered 
the upper Ohio valley before the col at (G) was eroded and the 
present drainage to the mouth of the great Miami established ; 
and there may have been still a sixth lake, though if there was, it 
was of less extent and shorter duration than any of the others. 
The abandoned channel (H) back of Petersburg, seems due to a 
projection or . “loop” of the glacier pushing out of Miami valley 
far enough to act as a dam to the new Ohio — which name is 
now first applicable to the river— and holding it back until its 
waters broke over the low divide that stood between old 
Laughery creek, and the ravine that came into the latter from 
the point (G). This is the only evidence that the ice ever 
reached the Kentucky side of the river, and it was not of suffi 
cient thickness to raise the water to the table-land. 
It is not to be supposed that each of these successive lakes 
was drained before the next was formed ; it is more probable 
that the gorge at (K) retained sufficient height to keep the 
present bottom . lands, at least the lower ones, continually sub- 
merged until long after the ice had begun its retreat. Neither 
is it necessary to assume a constant forward motion of the gla- 
cier; its advance may have been frequently interrupted, or there 
may even have been an occasional recession, without in the 
least invalidating the argument. The effect would be the same 
in the end, whether there was a continuous progressive motion, 
or an intermittent action. 
As nothing to the contrary has been said so far, it might 
be inferred that the Ohio, after first surmounting the col at (K) 
had an unchecked course to the Mississippi; but such was not 
the case. Kentucky river. Salt river (below Louisville), and 
possibly others, had a northward trend across the present Ohio 
valley into the state of Indiana. It is not known as yet, where 
they may have gone ; but it is certain that their outlets were 
choked up by the ice as were those of Kanawha and Licking. 
They had to find their way out in the same manner and by the 
same means. Of this, the canon at Leavenworth is ample evi- 
dence; and it is not until the mouth of Green river is reached, 
