on the Brfatic Ph^homena of Scandinavia. ITT 



Blanc, where the mean temperature is most probably about 

 — 9''-l, no glacier is formed; a fortiori, it would not form 

 with a mean of — 15°, which M. Durocher imagines to be that 

 of Spitzbergen. 



Like all the authors who have not specially studied exist- 

 ing glaciers. M. Durocher fancies that their ancient exten- 

 sion presupposes a very rigorous climate. Such is not the 

 case ; some very simple calculations prove it with conclusive 

 evidence.* 



M. Durocher terminates his memoir with this remarkable 

 concession : " Nevertheless, we must admit, that the glacial 

 theory has an indisputable advantage, that of introducing 

 agents which produce in our own days, but on a much smaller 

 scale, effects analogous to those which have taken place in 

 ancient times ; and it is this circumstance which has gained 

 over many adherents of late years ; while, in the diluvian 

 theory, the causes supposed to have been in operation do not 

 now perform the same functions as formerly, and, conse* 

 quently, do not produce, under our own eyes, effects altogether 

 similar to those of erratic phenomena ; thus we have not ob- 

 served, that the waters of rivers produce these erosions ill 

 form of fine striae." 



This confession is sufficient for the advocates of the an- 

 cient extension of glaciers. Their constant study has been 

 to shew, that the greater part of the phenomena ascribed to 

 diluvial currents, are still produced every day by glaciers ; 

 they have adopted the method introduced by M. Constant 

 Prevost into geology, — ." to explain facts which took place 

 before the historical era by natural agents, which are still in 

 operation.'* 



The diluvialists, at least M. Durocher, use a different lan- 

 guage. Existing currents, they say, do not produce effects 

 which they are endeavouring to explain, and yet there were 

 gigantic currents which produced them ; thus, by their own 

 confession, the greatest debacles, the most impetuous tor- 

 rents, the most extensiue inundations, cannot reproduce, on 



* Calculations similar to those here given will be found in M. Martins' paper 

 on the Glaciers of Chamonix, in our present number, p. 82 ; we have not, there- 

 fore, repeated them in this place.— i:rftt. Edin, Netv Phil. Jour. 



