616 THE JOURNAL OF GEOLOGY. 
particularly in and about New Haven, as well as with less minute- 
ness, over much of New England and in parts of New York 
state, accumulated the evidence, which has not only thoroughly 
proven the glacial theory, but has furnished the greater part of 
the fundamental facts upon which is built the present classifica- 
tion of the glacial period as given in his Manual. To be sure, 
many other workers have furnished abundant contributions and 
have greatly elaborated these facts, but when we examine the 
literature and observe the part Dana took, in formulating the 
grand outlines as well as many of the particulars of our general 
theory of the glacial period in America, we find his part in laying 
the foundation of opinion was far greater than that of any other 
one man. 
His papers in the American Journal of Science, beginning in 
1863 and not ceasing till the year 1893, are numerous, and are 
based upon his personal observations in the field. They cover 
the discussion of each of the important questions which enter 
into the present theory of the glacial period. Such were: the 
directions of strie and their relations to topography, with the 
establishment of the fact of their local deflection to follow the 
course of larger valleys, as the Mohawk, the Hudson Valley, the 
Connecticut River valley, etc.; the floods resulting from the 
melting of glaciers and the nature of evidence left by them; the 
absence of marine life in Long Island Sound through the glacial 
and part of the Champlain period; reindeer of Arctic type in 
southern New England; depression of land during the melting 
of the great glacier; damming of streams by ice; and Kames 
and their relations to the ordinary materials of drift. These, and 
many others of the particular phenomena of glaciation were built 
into the definition of the glacial period as he elaborated it from 
his personal observations. 
Even to his last days his interest in the glacial question was 
keen and wide. In the preparation of the fourth edition of the 
Manual, although confined to New Haven, he made a thorough 
revision of the chapters on that subject. He realized that out- 
side his quiet study hot controversies were going on among gla- 
