Ml* Murchison on the Glacial Theory, 1S7 



explicable, until the work of Agassiz unexpectedly threw a flood of light 

 upon his mind.* If Professor Hitchcock could demonstrate what he now 

 seems to believe, that the great mass of the continent of North America 

 was formerly covered with ice, he must first prove that it was not at that 

 period below the level of the sea ; but as yet no facts are before us to 

 lead us to doubt that the great accumulation of detritus and the trans- 

 port of blocks did take place beneath the waters in that country. In 

 justice, however, to this author, it must be said, that in expounding the 

 glacial theory he ingenuously acknowledges the great difficulty of believ- 

 ing that solid masses of ice 3000 to 4000 feet thick, covered the whole 

 region ; that no action of a glacier will explain the persistent striatiou of 

 the surface of an entire continent from N. to S. and that the direction 

 of the boulders and the strioo is to a great extent up-hill. When these 

 and many other difficulties shall have been carefully weighed, our trans- 

 atlantic friends may be disposed to modify their views, particularly when 

 they find that the existence of glaciers in Scotland and England (I mean 

 in the Alpine sense) is not yet, at all events, established to the satis- 

 faction of what I believe to be by far the greater number of British geo- 

 logists. 



The presence of Mr Lyell at this time in North America, is indeed 

 most opportune, for whatever changes his mind may have recently un- 

 dergone, no geologist has more strenuously laboured to make himself 

 master of all its bearings, or more systematically enlarged our knowledge 

 of this disputed subject. Possessing as he now does the advantage of 

 observation on a vast scale, I have little doubt that he will account for 

 the wide dispersion of blocks in America from N. to S., by referring to a 

 cause quite as general and quite as aqueous as that by which he originally 

 sought to explain the phenomena in Europe. t 



Although the consideration of this subject has already carried me beyond 

 the limits I had prescribed to myself, yet I cannot quit it without re- 

 minding you, that the greatest geological authorities on the Continent, 

 led on by Von Buch who has so long studied these phenomena in his 

 native land, are opponents to the views of Agassiz. Even whilst I write, 

 I find that M. de Beaumont has just communicated to the Institute of 

 France, a report on the results of a journey through liapland, Finland, 

 and the north of Europe, by his countryman M. Durocher,in which, group- 



* Anniversaiy Address. Philadelphia, April 1841, p. 24. I must be ex- 

 cused for stating that Professor Hitchcock has entirely misconceived my view, 

 when he places my name among those who had espoused the Alpine glacial theory. 

 My efforts have been invariably directed towards its limitation, nay, to its entire 

 rejection, as applicable to be by far the largest portions of the surface of the 

 globe. 



t See Principles of Geoh»gy. -d edit. vol. i. p. 3-t2 ; and Element:* of Gtologj-. 

 let edit. p. 1315. 



