268 Canadian Record of Science. 



We can scarcely doubt that the close connection of the 

 Atlantic and Arctic oceans is one factor in those remark- 

 able vicissitudes of climate experienced by the former, and 

 in which the Pacific area has also shared in connection with 

 the Antarctic Sea. ISTo geological facts are indeed at first 

 sight more strange and inexplicable than the changes of 

 climate in the Atlantic area / even in comparatively modern 

 periods. We know that in the early Tertiary, perpetual 

 summer reigned as far north as the middle of Greenland, 

 and that in the Pleistocene, the Arctic cold advanced until 

 an almost perennial winter prevailed half way to the 

 equator. It is no wonder that nearly every cause available 

 in the heavens and the earth has been invoked to account 

 for these astounding facts. 



It will, I hope, meet with the approval of your veteran 

 glaciologist Dr. Crosskey if, neglecting most of these theo- 

 retical views, I venture to invite your attention in con- 

 nection with this question chiefly to the old Lyellian doc- 

 trine of the modification of climate by geographical changes. 

 Let us, at least, consider how much these are able to ac- 

 count for. 



The ocean is a great equalizer of extremes of temperature. 

 It does this by its great capacity for heat, and by its cooling 

 and heating power when passing from the solid into the 

 liquid and gaseous states, and the reverse. It also acts by 

 its mobility, its currents serving to convey heat to great 

 distances or to cool the air by the movement of cool icy 

 waters. The land, ou the other hand, cools or warms 

 rapidly, and can transmit its influence to a distance only by 

 the winds, and the influence so transmitted is rather in the 

 nature of a disturbing than of an equalizing cause. It fol- 

 lows that any change in the distribution of land and water 

 must affect climate, more especially if it changes the char- 

 acter or course of the ocean currents. 1 



At the present time, the North Atlantic presents some very 

 peculiar and in some respects exceptional features, which are 



1 Von Woeickoff has very strongly put these principles in a Review 

 of Croll's recent book, Climate and Cosmology ; American Journal of 

 Science, March, 18S6. 



