134 



The Glacial Theory. 



the country of Wicklow, and Cuileagh, also seem to me to form 

 so many separate groups, as regards the dispersion of their erratic 

 blocks. But these relations of the blocks to the chains of moun- 

 tains are only one of the peculiarities of their arrangement; it is 

 indeed that very one which has been least insisted on, and with 

 which the defenders of the theory of currents have the least occu- 

 pied themselves; and yet they ought above everything to have 

 endeavoured to explain it, because it includes facts the most con- 

 trary to their theory. How is it really possible to attribute to an 

 eruption of the ocean, or to the effects of a continual soulevement, 

 the dispersion of different groups of erratic blocks arranged like a 

 fan around each particular system of mountains ? How, moreover, 

 is it possible to conceive the existence of so many deep lakes, by 

 whose beds, however, all these currents must nevertheless have pass- 

 ed, in order to perch the erratic blocks on the flanks of the moun- 

 tains, rather than accumulate them in the bottom of the valleys ? 



" A circumstance which further adds to the importance of these 

 scattered blocks and continuous mounds, is, that the valleys in 

 which they are met with have generally their walls more or less 

 worn, rounded, smoothed, polished, and scratched. Now, this par- 

 ticular appearance is evidently to be attributed to the same cause 

 which transported the blocks; for these two series of facts are every- 

 where intimately connected together. 



" It was in England and in Sweden that the first polished sur- 

 faces were observed, and these were everywhere attributed, until 

 recently, to the action of great currents, without any regard being 

 paid to the improbability of a current, or rather currents, spouting 

 like springs from the top of all the valleys, and being sufficiently 

 powerful to convey from their place of origin blocks sometimes of 

 immense dimensions. It can easily be imagined, that, at a period 

 when almost all geological phenomena were attributed to the action 

 of water, no endeavour was made to search for another cause for the 

 transport of erratic blocks. But if a comparison had been institut- 

 ed between the polished surfaces and the effects produced by cur- 

 rents, very remarkable differences between them would have been 

 discovered. As I have said elsewhere, rocks polished by glaciers 

 of the present day present surfaces gently rounded, smooth, and 



