200 Bibliography. 



labors of England, Scotland, and Ireland, and the wide-ranging re- 

 searches that are in progress in this country. 



Mr. Murchison takes honorable notice of the labors of Mr. Lyell 

 among us, and of the co-operation of American geologists with him in 

 carrying out his personal review of the great features of our geology. 

 We must, however, find room, in the very winding up of our number, 

 for adding, that Mr. Murchison has reviewed, with a faithful severity, 

 the wide extension attempted to be made of the beautiful glacial theory 

 of Agassiz, so splendid and satisfactory in its application to the Alps, 

 and to all other regions where glaciers exist, or can have existed in 

 past ages. This great subject, and with it that of drift and bowlders, 

 the President discusses with his accustomed ability and independence, 

 and prescribes some wholesome restraints to those whose imaginations 

 would allure their judgment to unsustainable conclusions. 



We are not willing, however, to omit the following citation, with 

 which we shall conclude our notice : 



" The other point to which I allude, and bearing at once on this 

 view, is a discovery which our librarian has just made without quitting 

 the apartments which he so truly adorns. In the American Journal of 

 Science for the year 1826, vol. x, p. 217, Mr. Lonsdale has detected a 

 short, clear, and modest statement, entitled ' Remarks on Bowlders, by 

 Peter Dobson,' which, though little more than one page in length, con- 

 tains the essence of the modified glacial theory at which we have arri- 

 ved after so much debate. First describing in a few lines the manner 

 in which large bowlders, weighing from ten cwt. to fifteen tons, were 

 dug out in clay and gravel, when making the foundations for his own 

 cotton factory at Vernon, and seeing that it was not uncommon to find 

 them worn, abraded, and scratched on the lower side, ' as if done (to 

 use his own expression) ly their having been dragged over rocks and 

 gravelly earth in one steady position,'' he adds this most remarkable 

 sentence : ' I think we cannot account for these appearances, unless we 

 call in the aid of ice as well as water, and that they have heen zoom by 

 being suspended and carried in ice over rocks and earth under loater.'' 

 To show also that he had read much and thought deeply on this sub- 

 ject, Mr. Dobson quotes British authorities to prove, that as ice-floes 

 constantly carry huge masses of stone, and deposit them at great dis- 

 tances from their original situation, so may they explain the transporta- 

 tion of foreign bowlders to our continents. 



" Apologizing therefore for having detained you long, and for hav- 

 ing previously too much extended a similar mode of reasoning, I take 

 leave of the glacial theory in congratulating American science in hav- 

 ing possessed the original author of the best glacial theory, though his 

 name had escaped notice ; and in recommending to you the terse ar- 



