Mr. Dodge spoke yesterday afternoon in the Geological Lecture Hall of the University Museum on "Some of the Geological Conditions that have Influenced the Development of the United States."

Mr. Dodge began his lecture by a consideration of the effect of the geology of the United States on its agriculture. Our ancestors, when the Atlantic strip stretching from Maine to Florida was first discovered, settled where the agricultural conditions were good. Owing to the barrier formed by the Appalachian Mountains, the early colonists remained east of these mountains until this area was thickly settled. The unity of interests, brought about by this close association of the colonies, made possible a successful revolution against the mother-country. As the pressure increased within this narrow strip of land, emigration pushed out through the passes of the Appalachians. The Kentucky Blue Grass country was then developed and as the tide flowed across the Mississippi, the great prairies of the west were taken up, until the Bad Lands at the base of the Rocky Mountains checked the emigrants. At this point, the difficulty of advance was so great that it was easier to go around the Horn to San Francisco than across the Bad Lands and the Rockies. When the railroads were put through, however, progress was rapid.

Commercially, no better example of the effect of geological conditions can be seen, than the case of New York. A commercial centre is always at the junction of two or more lines of transportation. New York has not only the Hudson with its tributaries, and the railroads which follow the rivers, but also a good egress to the sea. In former geological ages the Hudson was merely a river valley. Now, however, by the tipping of the land through which it flowed, the Hudson has become the deep sea way, which has made New York the greatest commercial centre in the United States.

In regards transportation, not only ships but all other methods of conveyance follow the courses allowed them by the geological formations which surround them. This is especially well illustrated by the frequency with which the railroads follow the course of the streams. And as the settlement and growth of a country depends to a great extent on transportation, so transportation depends entirely on the geological features of the country.

In early times, our manufacturing towns were situated near water power. Thus many of our towns owe their positions to their nearness to waterfalls. Later with the introduction of cheap transportation and the displacement of water power by coal, manufacturing industries moved to the coal regions or commercial centers.

In conclusion, Mr. Dodge gave many stereoptican views illustrating points touched upon in his lecture.