1892 - 1893 
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I remained in charge of the archeologic. field 
work of the Bureau of Ethnology with Fowke, Mindeleff and 
Dinwiddie as assistants, personally making important studies 
in several states. I examined in detail the novaculite 
quarries of Arkansas, the pipestone -quarries of Minnesota, 
and the Ancient copper mines of Isle Royale, Michigan. I 
also made important studies at various points in the valleys 
of the Potomac, Genesee, and Ohio rivers, and my surveys and 
examinations In Delaware Valley, particularly about Trenton, 
were extended and important. At the last-named locality 
advantage was taken of the excavation of a broad and deep 
trench, designed for railway extension parallel with the 
river front at Trenton, to study carefully the late glacial 
gravels commonly supposed to yield human relics. For a 
period of six weeks the excellent exposures made in this 
trench, 25 to 35 feet deep and miles in length, were constant- 
1y watched by me and Dinwiddle, without finding a single 
artificial object In the previously undisturbed gravels. This 
negative result is of great importance due to its bearing on 
the question of the geological antiquity of man. 
In December 1892, I was placed in charge of the 
exhibit of the Bureau of Ethnology for the World T s Columbian 
Exposition at Chicago, and several months were occupied main¬ 
ly in preparing, classifying, labeling and arranging the 
