THE 
(OUR EOF GEOLOGY 
Cenenek NOVEMBER, 1507 
A GROUP OF HYPOTHESES BEARING ON CLIMATIC 
CEANGES: 
WuiLe the atmosphere is the most active of all geological 
agencies, it has received the least careful study from geologists. 
Its very activity destroys its relics almost as soon as formed 
and gives them peculiar evanescence. This has invited the 
neglect of geologists laudably prone to concentrate their 
attention upon agencies which have left enduring and unequivo- 
cal records. The atmospheric element in geological history bids 
fair to long remain obscured by elusive factors and uncertain 
interpretations. None the less it is an element of supreme 
importance and should be persistently attacked until it yields up 
its truths. This must be my excuse for offering a paper which, 
I am painfully aware, is very speculative in many of its parts. 
All our attempts at the solution of climatic problems pro- 
ceed on some conscious or wuconscious assumption concerning 
the extent and nature of the atmosphere at the stage involved. 
These assumptions are too often unconscious and the conclusions 
reached command a confidence which might not be reposed in 
them if the underlying assumptions were frankly stated. It may 
not be unwholesome, therefore, to raise some radical doubts 
respecting current assumptions regarding the early stages of the 
tRead before the British Association for the Advancement of Science at Toronto, 
August 20,1897. For obvious reasons it was necessary to treat the many factors 
involved with extreme brevity and hence with some obscurity and much lack of ade- 
quate qualification. I have taken the liberty of adding some tables and other matter 
Vole NOT 7: 653 
