1# A Period in the History of our Planet. 



Cordilleras and Newbold's at Seringapatam shall be confirmed, 

 and to these we may subjoin those made by earlier travellers 

 upon Atlas and Lebanon, the whole surface of the earth was, ac- 

 cording to all probability, for a time one single uninterrupted 

 surface of ice, from which projected only the highest moun- 

 tain-ridges covered with eternal snow. The limits which would 

 seem to be indicated by the various phenomena which we shall 

 afterwards treat of, are very probably referable to a subse- 

 quent epoch, when the universal ice-crust had already begun 

 here and there to disappear, and particular tracts to emerge 

 like oases in the immense icy desert. Be that, however, as it 

 may, this much is certain, that, upon the northern half of the 

 European- Asiatic continent, there have been found only few, 

 and proportionally unextensive districts, which do not bear im- 

 pressed on them the traces of former envelopement in ice, and 

 that in the excepted places the configuration of the surface 

 has been decidedly unfavourable to the preservation of such 

 traces. 



But it is only a few years since the great importance of the 

 phenomena, which have remained as traces of the glacial pe- 

 riod, for the general physical history of our earth, was sur- 

 mised ; the number of naturalists who occupied themselves in 

 searching out these traces was but few ; still fewer, I may 

 venture to say, understood how to find them ; many would 

 not even see what they did find ; and thus it need be nowise 

 surprising that more exact accounts cannot bo given respect- 

 ing the ubiquitous extension of the ice-covering, its spread- 

 ing towards the south, &c. 



We have certain data with respect to the height to which 

 this ice-covering had swollen, and with respect to the thick- 

 ness which it must have reached in many places. I have fol- 

 lowed its marks along the coasts of England, Scotland, and 

 Ireland, and no doubt can now be raised in regard to the fact 

 that in our latitudes the ice extended to below the level of the 

 present sea. At many points of these coasts I have, as far as 

 my eye could penetrate the water, seen these traces deep be- 

 low the surface ;* and so indelible are these traces, so deeply 



* Hence there can be no doubt, that, if a north sea did exist at that time, its 

 level must have been much lower than it is at present ; for it is established; by 



