Page:Popular Science Monthly Volume 38.djvu/763

Rh entered the present channel of the Ohio near Lawrenceburg, Indiana.

At the present time the Ohio passes by the city of Cincinnati and follows a channel cut between the hills at a more recent period than the greater portion of its bed. At the time of the existence of the old valley extending north from Cincinnati, a barrier of land extended across from Ohio to Kentucky and barred the way of the river to the west. This was cut down probably



at the time the country was occupied by the glaciers, and as a result we find in the present bed of the stream immense banks of coarse gravel alternately on the Kentucky and on the Ohio side for some miles below Cincinnati, while near the mouth of the Big Miami is another immense deposit which resulted from the melting of the glaciers as they retired northward up that valley.

The consequences of the stoppage of the current of the river are plainly seen. The glaciers creeping down from the north would naturally follow the old channel of the river and prevent its egress to the north, so it was probably during the on-coming