462 REPORT OF NATIONAL MUSEUM, 1904. 



The merits of the case can not here be decided, but it would seem 

 most probable that this otters but another illustration of the experi- 

 ences of every executive who has planned, directed, and rendered 

 possible the work of subordinates, only to find in the end that the 

 value of his instrumentality is quite underestimated, and all credit 

 claimed by him to whom opportunit} r was given. 



In 1856 Dr. Edward Hitchcock came once more to the front through 

 the medium of the Smithsonian Contributions to Knowledge with a 

 paper of some 150 royal quarto pages and 12 plates. In this he con- 

 sidered all changes which had taken place since the 

 Hitchcock's close of the Tertiary period as belonging to the "allu- 



Illustrations of ,. ,: , ' .,, . 



surface Geology, vial formation, an d d ue to causes still m operation. 

 The products of these changes he classed as (1) drift 

 unmodified and (2) drift modified, under the latter including such 

 deposits as beaches, ancient and modern; submarine ridges; sea bot- 

 toms; osars; dunes; terraces; deltas, and moraines. The drift proper 

 he regarded as a product of "several agencies — icebergs, glaciers, 

 landslips, and waves of translation" — which, though more active in 

 the past than now, are still at work. The sandy and gravelly plains 

 (the overwash of modern geologists) and the low ridges of New Eng- 

 land were thought to represent old sea bottoms, to be ""explained only 

 by the former presence of the ocean above them, with its tides and 

 currents." 



The terraces of the Connecticut River were described in great detail, 

 with numerous references to those of other regions, both at home and 

 abroad. The chief agency in the formation of these appeared to him, 

 and rightly, to have been water. Moraine terraces, however, demanded 

 the action of stranded icebergs in addition. To account for the drift 

 accumulations at various altitudes, he conceived that the ocean water 

 . must have stood some 2,500 feet above its present level. He conceived 

 further "that all the northern part of this continent, at least all east 

 of the Mississippi, had been covered b}^ the ocean since the glacial 

 period," in this agreeing with Agassiz. As to the origin of the mate- 

 rial of the "irregular coarse deposit beneath the modified beaches and 

 terraces," he agreed essentially with the German geologist, Naumann, 

 in supposing that: (1) The eroding materials must have been commi- 

 nuted stone; (2) they must have been borne along under heavy pres- 

 sure; (3) the moving force must have operated slowly and with 

 prodigious energy, and (1) moving in a nearly uniform direction, 

 though liable to local divergence; (5) the vehicle of the eroded mate- 

 rial could not have been water alone, (6) but a firm and heavy mass, 

 somewhat plastic. "Where, now, save in glaciers, icebergs, and ice 

 islands can we find agencies that meet the conditions of the above 

 principles respecting drift?" The exact period of operation of the 

 drift agency naturally he found difficulty in determining. He felt 



