MICHIGAN ACADEMY OF SCIENCE. 
139 
dinavia to show how the line falls passing from the interior, where 
the mean of six latitudes is 4,233 feet, to the coast, where it is only 
3,566 feet. While these figures for Scandinavia may be correct as far 
as they go, they do not really meet the objection that the Gulf Stream, 
carrying warm ocean water to the British Isles makes their climate 
much milder than that of Labrador which is in the same latitude on the 
other side of the same ocean, while as between the two sides of North 
America the western enjoys a much milder climate as a result of the 
ocean in its Vicinity being warmed by the Japan Stream. Similarly, in 
the southern hemisphere, we may note the fact discussed by Darwin* 
that the Antarctic Current gives the islands of South Georgia an 
almost glacial climate, with fauna and flora to match, 
with a riotous vegetation on Terra 
del Fuego in 
the 
as contrasted 
same latitude. 
South Georgia is considerably nearer to being permanently glaciated 
than is Iceland although the latter is ten degrees nearer the pole. But 
Iceland has the Gulf Stream. Conditions as actually observed indicate 
that cold oceans give cold land climates and vice versa, not that glacia- 
tion is produced by warm oceans. 
But turning to differential altitude again it is evident that before 
the ocean cooled enough to reach the critical stage postulated by 
Professor Frankland, it must have approached fairly close to its present 
temperature and volume, so that the altitude of the land surfaces above 
it could play no important part in producing the Glacial Epoch. The 
excess of evaporation then over what it is now may be fairly assumed 
to have been largely taken up in the production of glacial ice, so that 
in that ice we ought to have a measure which would express bj r far the 
greater part of the deficiency of ocean volume below the present. We 
shall see in a moment that instead of indicating a lowering of the 
oceans or a rise when melting occurred, to the extent which our obser- 
vational data demand, say 5,000 or 6,000 feet or more, the volume of 
water so fastened upon the land is wholly insufficient. 
There are, therefore, several very good reasons why terrestrial heat, 
transmitted to the oceans, cannot be accepted as an explanation of such 
a low ocean level during the Glacial Epoch nor of the rise of the ocean 
to the height of a mile or more at the close of that epoch. The volume 
of the ice may be accepted as a fair approximation to the amount of 
fluctuation in the volume of the sea. 
There is much geological reason for the prevalent belief that in 
Eocene time the oceans were considerably warmer than later, in fact 
that they continued to cool throughout Tertiary and Glacial time, so 
that if the earth were partially denuded of an outer cooled crust at the 
end of the Cretaceous period and the Tertiary opened with hot and 
shallow seas the record might read about as it does, there being a num- 
ber of blank pages to start with because the first marine deposits would 
tend to be nonfossiliferous. That being the case, it does not appear to 
have taken all of Eocene time for the oceans to cool down to biological 
temperatures and in the remainder of Tertiary time they cannot have 
differed in temperature to a very marked degree from what we see today. 
We have next to investigate the extent to which glaciation must be 
reckoned with as a modifier of ocean volume. 
*Darwin, Charles, “Journal of Researches on the Voyage of the Beagle.’’ 
