TIIK ]('K A<!K TX CAXADA. 



liy fuels to insist on the lullowing' n'lvat Iciidiiij;' ]iriiicii»les 

 as to tlic uliU'iiil ]icrio(l and its causes: — - 



1. Tlic ])li('noiii('nii iirc not to lie ('\])lain('(l liy any one 

 cause or liy any one iiieal all-eniliraeinn' hypothesis, l)ut 

 liy a in<ire aeti\e and e.\ti'nsi\e. o|)evalion of many of the 

 ordinary causes still exisiiiiL!,- in the more northern ren'ious. 



2. The astrononueal changes which lane lieen in\oked 

 to account for cold climate, not e\ce])tinL;' those advocated 

 liy ('roll and I)all, are incai)alile of fully e.\]ilaiinnu; the 

 facts as now actually ascertained. 



.'-). Thei-e lias not. been at any tinu' a polar ice caj», and 

 the theory of j^'reat continental ice sheets co\-ci'in,i,f the 

 iiorthei'ii ])arts of the twou,ix'at continents is also liasidess. 



4. 'J'he ]ihen()niena indicate! the action of local mountain 

 glaciers of great volume, along with that of lloating ice 

 in various forms, and this HKjre es})ecially in periods of 

 suhsidence of the land. 



5. The cold climate of the glacial ])eriod was mainly a 

 re.sult of jieculiar geographical conditions ami a dilTerent 

 distrihution of ocean curi'ents, and was not so much 

 characterised bv general low tennierature as bv the local 

 occurrence of extreme evajioration and condensation. 



G. The close of the glacial period is not very remote, 

 and cannot have antedated by many ciMituries or mil- 

 lenniums the first a])pearance of man, as known to us iu 

 history. 



These theses I have maintained in papers whoso dates 

 reach back to LSoo, and in addresses delivered to the 

 ]>ritish and American Associations and to the Natural 

 History Society of ^Montreal, and in popular works on 

 geology. They still a])pear to me to he true, notwilli- 

 standing the wa\'e of extreme glacial ideas that has been 

 passing over the world. lUit I am glad to see that a 



