DRIFT DIVISION. 223 
to other parts of the earth’s surface, but because the facts upon which the arguments are 
based are more familiar to me, and have come mostly under personal observation. 
It cannot but be admitted, from the various facts detailed on the transportation of boulders 
and drift, and the scratched surfaces of rocks, first, that the topographical features of the 
country were, at the drift period, in the main, the same as at present; secondly, that the 
same dynamical law that novo causes the Labrador current to trend to the westward along the 
American coast, acted in former times when most parts of the United States were buried 
beneath the waters of the ocean ; and thirdly, that the same dynamical law that causes the 
flow of the Gulf stream, must then have caused a part of that stream to flow from the Gulf 
of Mexico through the Mississippi valley at the drift period ; and owing to its greater rotative 
velocity in the tropic than as it progressed towards the north, it would have a tendency to an 
eastwardly flow from that valley. 
To the action of these two currents as main causes, influenced by the dynamical laws 
above referred to, and the topographical features of the country, when mostly beneath the 
waters of the ocean, we would ascribe the phenomena of the drift deposits. 
Influences of these currents in the distribution of the drift. 
The northern current from Hudson’s bay and the Polar seas, with its ice loaded with 
northern rocks, flowing over the northern parts of the United States, would be met by the 
warm waters of the Gulf stream, and cause most of the freight of the ice to be deposited 
within a few degrees of latitude, as we see in the ocean at present. To this cause I ascribe 
the vast amount of the drift deposits of Ohio, Indiana, Illinois, Northern Missouri, Iowa 
territory, Wisconsin territory and Michigan; as the main valley of communication between 
the Polar seas and the Gulf of Mexico is through the Mississippi, Upper Mississippi and 
St. Peter’s, and Red river of the North, to Hudson’s bay and Mackenzie’s river. This great 
valley is several hundred miles wide in some parts. The warm current would flow on to the 
northward, superimposed on the cold current which would continue southwards beneath the 
other, and transport fine materials, as we see in the Mississippi valley, of the detritus of rocks 
far to the north, as has been already explained. 
The eastwardly tendency of the Gulf stream arising from an obedience to the dynamical 
law, influencing its rotative velocity derived from its inertia, would cause the current to be 
deflected from the Mississippi valley. The main outlet of this part of the Gulf stream, flow¬ 
ing up the Mississippi valley, and bearing to the eastward, would be through the valley of 
the Great lakes, across Illinois, Indiana, Michigan, Ohio, Missouri, Iowa and Wisconsin ; and 
to the influence of this warm water from.the south, I attribute the scarcity of erratics south 
of the Ohio and Missouri, and of the elevated region in Pennsylvania and New-York, south 
of the Lakes Erie and Ontario and the Mohawk valley, to the Catskill mountains. 
There can be no doubt, on a review of the facts narrated, that the scratches on rocks are 
due to the movements of floating ice, containing masses of rock frozen in, and grinding upon 
