Bulletin of the Scientific Laboratories of Denison University. 
Voi. XI. Article I, with i Map. March, 1898. 
PRE-GLACIAL DRAINAGE IN THE VICINITY OF 
CINCINNATI; ITS RELATION TO THE ORIGIN 
OF THE MODERN OHIO RIVER, AND ITS BEAR- 
ING UPON THE QUESTION OF THE SOUTHERN 
LIMITS OF THE ICE-SHEET. 
By Gerard Fowke, 
P'or more than sixty miles below the mouth of the Little 
Miami, the Ohio river flows through a tortuous channel. The 
dial of a compass fixed on a steamer will, in that distance, make 
a complete circuit under the needle. Much of the way the 
outer curves sweep over rocky detritus fallen from rugged hills 
crowned with precipitous bluffs; opposite these the inner curves 
flow gently over sand-bars bordering terraced bottom lands. 
The variation in the width of the valley is considerable ; at 
times the upland on one side recedes, and a wide bottom inter- 
venes between its foot and the river ; again, the hills approach 
each other until only a narrow strip of alluvial soil is found. 
For fifty miles above the Little Miami different conditions 
prevail ; the valley is more uniform in breadth, the hills have 
gentler slopes and more symmetrical contours. The geological 
formation within this area is identical, all of it lying in the Cin- 
cinnati or Hudson River group ; measured vertically, there is 
about one foot of compact blue limestone to ten feet of gray or 
bluish clay. Such a combination does not readily lend itself to 
the construction of cliffs by atmospheric erosion ; while the 
close texture of the clay and its extension below surface drain- 
age lines, precludes such disintegration of lower strata as would 
result in cliffs due to great landslides or the downfall of large 
masses of rock. The topography above the Little Miami is 
norrnal, while the phenomena below that point are quite differ- 
