DRIFT DIVISION. 
211 
ware, Susquehannah and Ohio, are northwardly, generally west of north ; those at lower 
levels, but considerably elevated, are intermediate between the directions last mentioned, and 
the general trend of the valleys in which they are located ; while those in the lower parts of 
main valleys, conform more nearly to the general directions of those valleys. 
The local variations from these as general directions, are nearly all susceptible of satisfac¬ 
tory explanation, when we take into view the topography of the country, and the deflections 
and eddies that would be produced in currents, by meeting such a contour of bottom and 
shores, as the present form of the surface would produce if it were covered with water. 
It is unnecessary perhaps to go into a detail of examples to show this result; but there are 
two striking exceptions, as they would appear to be, to one unacquainted with the topogra¬ 
phical features of the country. The most striking is that of the elevated lands along the 
eastern part of New-York and western part of Massachusetts, where, by referring to the 
tables, the reader will perceive that the scratches are mostly from northwest to southeast. 
The phenomena that have been related indicate, that at some former time, the country, to 
the tops of the high mountains, was covered with water, and that strong currents flowed 
through the Mohawk and the Champlain and Hudson valleys. The great depth and breadth 
of the Mohawk valley is sufficient, it is believed, to have given direction and force to that 
volume of water flowing through it, to be felt and made manifest by the abrasion of masses of 
rock, to as great a distance as where the facts were observed by Prof. Hitchcock and myself. 
I have studied with some care the topographical features of Massachusetts as well as New- 
York, and believe that all the apparent anomalies of direction of the scratches may be recon¬ 
ciled upon similar principles, taking an enlarged view’- of the topographical features of the 
country, and considering the general directions that would be given to currents flowing over 
and among them, the local eddies and deflections caused by the irregularities of the ground, 
and another cause that will be mentioned in its proper place, when discussing the direction 
of currents. 
The other principal exception is on the northwest side of the great valley, between the 
Highland mountains on the southeast, and the Catskill mountains and their prolongation on 
the northwest. The tables show many scratches from the east and east-northeast, and some 
even from the southeast; but they nearly all conform to the rule that is almost universally 
found to hold true, viz. that the scratches high on the sides of the valleys are laterally oblique to 
the direction of the main valley; and this valley seems to have been originally the main valley, 
or the prolongation of the Champlain and Hudson valley to the southwest. 
Summary of the Facts on the Drift Deposits. 
1. The surface of the earth throughout the First district of New-York, and in fact throughout the 
whole northern portion of the United States, included in the great valleys of the St. Lawrence, 
the Upper Mississippi, and north of the Ohio river, and also through the northern parts of 
