72 THE PREGLACIAL DRAINAGE OF OHIO. 



through the gap. The mythical "Lake Ohio," which is cur- 

 rently believed to have resulted from a blocking of the Ohio 

 river by the glacier, would be insignificant by comparison — 

 admitting, for the sake of comparison, that it ever existed as so 

 frequently described. The area of the real lake, created by 

 the Madison dam, can be ascertained only by carrying the level 

 at which it stood at its outlet, up the Kentucky, Great Miami, 

 Licking, Big Sandy, Kanawha, and across central Ohio toward 

 the headwaters of the Tuscarawas. Until this level is ascer- 

 tained we cannot know how much of the country was sub- 

 merged, or how many of the existing high areas were drowned. 

 Neither have we any means at present of knowing how long 

 these conditions prevailed. They may have lasted until the 

 col had worn low enough to drain off most of the accumulated 

 water. On the other hand, the advancing ice may have pushed 

 this water in front of it, and maintained a constantly diminishing 

 lake until its most southern limit was reached. If we may sup- 

 pose the former supposition to be the correct one, then a new 

 river was established ; following the Kanawha as far as the 

 mouth of the Licking-Kentucky, and that stream, reversed, 

 from there toward the south and west. 



In time, the encroaching ice covered the site of its junction 

 with these two rivers, and Kanawha was again deprived of an 

 outlet. A second lake was formed, including the basin of the 

 Kanawha and all its tributaries east of the Licking. It in- 

 creased in area and depth until it surmounted the col at (A) ; 

 flowing over this divide, its waters would follow old Limestone 

 to its junction with the Licking at the point (G), thence north 

 to Hamilton, and so find their way to the Kentucky. 



The glacier reached Hamilton, and for the third time a lake 

 was formed. Both Kanawha and Licking were now shut off; 

 the water rose over the col at (C). The Kanawha reached this 

 by following old Limestone as before to (G), and thence down 

 the Mill creek valley. Pushing through the gap at North Bend, 

 and past Cleves, they reached the Kentucky along the bed now 

 occupied by the Great Miami below that village. 



When the ice came to the hills about Cincinnati, the mouth 

 of old Limestone at (G) was obliterated, and for the fourth time 



