894 



REPORT OF NATIONAL MUSEUM, 1904. 



knowledge regarding" glacial transportation, found difficulty in account- 

 ing for the same. He recognized the similarity of the trains to the 

 lateral glacial moraines described by Agassiz in his Etudes sur les Gla- 

 ciers, which had appeared five years previously, but could not con- 

 ceive of a glacier traveling directly across the intervening ridges, even 

 were the mountains in the vicinity of sufficient altitude to give rise to 

 the same. Neither did the consideration of river drift or floating ice 



afford him a satisfactory 

 conclusion. "In short, 

 I find so many difficul- 

 ties on an}^ supposition 

 which I may make that 

 I prefer to leave the case 

 unexplained until more 

 analogous facts have 

 been observed. " 



Unsatisfactory and ap- 

 parently unimportant as 

 the paper may, at first 

 thought, seem, it is men- 

 tioned here on account 

 of the extraordinary ex- 

 planation .of the phe- 

 nomenon offered hy the 

 Rogers brothers three 

 years later (see p. 403). 

 In the American Jour- 

 nal of Science for 1845 

 W. W. Mather, whose 

 work in New York and 

 Ohio has been already 

 mentioned, published a 

 paper on the physical 

 geography of the United States in which' he still further elaborated 

 some of the interesting and rather unique ideas regarding the origin 

 M ., .. of the -secondary rocks and the elevation of islands, 



Mather on the J 



Physical Geology of continents, and mountain chains which he there put 



the United States, ' r _ 



,84S - forth. These may be referred to in considerable detail. 



Mather again argued on the basis that the earth is a cooling body, 

 contracting, and hence undergoing an increased velocity of rotation 

 upon its axis. The oblateness of its spheroidal form, due to the 

 increase of centrifugal force, would therefore induce a flow of water 

 from the polar to the tropical regions, and as the earth revolved from 

 west to east these currents from the poles would bend more and more 



Pig. 39.— Richmond Bowlder Train. (After E. Hitchcock. 



