Apparent objections to the Glacial Theory. 297 



from whence they are lifted, or by the action of the river currents 

 which have brought them down from the land. At the time when 

 the present lands were submerged therefore, there could have been 

 no rivers to furnish detritus, for allowing that some land existed in 

 the northern hemisphere, yet such would have consisted only of 

 rocky islands such as the summits of the present mountains might 

 produce, and consequently would have been unable to furnish rivers 

 of any moment; the detritus therefore which is now scattered over 

 the continents of the north, should consist chiefly of the angular 

 fragments which the frost had detached from rocks in situ, and 

 not of rounded or water-worn pebbles and boulders. Lyell endea- 

 vours to shew, that the rounding of erratics is to be attributed to 

 the action of frost, and not to the attrition of moving waters, and 

 he cites the granite used in the buildings of Quebec to show the 

 correctness of his views. This, however, is founding a general rule 

 upon one nearly solitary exception, for while the Quebec granite re- 

 quires to be coated over with oil and paint, in order to preserve it 

 from exfoliation, we do not hear of the same necessity existing else- 

 where in regard to all granites ; and this is proved from what Lyell 

 himself tells us regarding the icebergs which were seen " in Sir 

 George Eyre's Sound in the latitude of Paris, which were seen in 

 1834 carrying angular pieces of granite, and stranding them in 

 fiords, where the shores were composed of clay slate." — LyeWs 

 Prin. Geol p. 379. 



While therefore the rounding of erratics composed of the Quebec 

 granite may be attributed to the agency of frosts, the same rule 

 will not apply to all, nor yet to the generality of blocks ; and thus 

 the instance quoted, forms but an exception, and is of little value in 

 determining the cause which has rounded almost all boulders and 

 detritus, of whatever rock composed.* M. Lariviere relates, that 

 "being at Memel on the Baltic in 1821, when the ice of the river 

 Niemen broke up, he saw a mass of ice thirty feet long which had 

 descended the stream, and had been thrown ashore. In the middle 



* It is proper to add, that my friend Lieut. R. B. Smith informs me, that in the 

 primary districts of Southern India, the granite blocks are subject to similar ex- 

 foliation from the effects of atmospheric agents, and have all the appearance of 

 having been subjected to aqueous attrition. 



