Page:Popular Science Monthly Volume 34.djvu/42

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32
THE POPULAR SCIENCE MONTHLY.

The geologic evidence of the environment of the celt-users of the Delaware River is complete and intelligible: the continuity of the deposits proves that the Trenton gravels were laid down while the northern part of the country was occupied by ice, and while

Fig. 5—Stereogram of the Present Head of Delaware Bay.

the terminal moraine was forming; their structure and composition prove that they were laid down in shallow floe-bearing waters; their distribution indicates unmistakably the geography