Page:Popular Science Monthly Volume 68.djvu/311

Rh material, transported by a mighty current of water which, he supposed, rushed over the land during the last grand deluge, accounts of which had been handed down by tradition and preserved in the archives of all people. "Although," he says, "it is commonly supposed that the deluge was intended solely for the punishment of the corrupt antediluvians, it is not improbable that the descendants of Noah reap many advantages from its influence, since the various soils underwent modifications and admixtures which render them better adapted for the wants of man. May not the hand of benevolence be seen working even amid the waters of the deluge?" he asks. It is, perhaps, doubtful if the hard-fisted occupants of many of Maine's rocky farms would be disposed to take so cheerful a view of the matter.

Substantially the same views were advanced by Jackson in his report on the geology of Rhode Island, which appeared in 1839.

There can not remain a doubt but that a violent current of water has rushed over the surface of the state since the elevation and consolidation of all the rocks and subsequent to the deposition of the Tertiary clay, and that this current came from the north. . . . Upon the surface of solid ledges, wherever they have been recently uncovered of their soil, scratches are seen running north and south, and the hard rocks are more or less polished by the currents of water which at the diluvial epoch coursed over their surfaces, carrying along the pebbles and sand which effected this abrasion, leaving stria, all of which run north and south, deviating a few degrees occasionally with the changes of direction given to the current by the obstacles in its way.

He did not accept the theory of drifting icebergs; 'nor,' he wrote, 'can we allow that any glaciers could have produced them by their loads of sliding rocks, for in that case they should have radiated from the mountains instead of following a uniform course along hillsides and through valleys.'

Although primarily a paleontologist, Timothy Conrad was sometimes drawn out of his chosen field by phenomena too obvious to be overlooked and concerning the nature of which little was actually known by the best authorities. The occurrence of enormous boulders in the drift, resting often upon unconsolidated sand and gravel, fell within this category. That such could not have been brought into their present position through floods was to him obvious, neither could they have been floated by ice floes from the north during a period of terrestrial depression. He assumed, rather, that the country previous to what is now known as the glacial epoch was covered with enormous lakes, and that a change in climate ensued, causing them to become frozen and converted into immense glaciers. At the same time elevations and depressions of the earth's surface were in progress, giving various degrees of inclination to the frozen surfaces of the lakes, down which boulders, sand and gravel would be impelled to great distances from the points of their origin. The impelling force, he thought, in some cases might be gravity alone, but during the close of the epoch,