The Geographical Journal (Journal of the Royal Geographical Society): Volume XII, No. 2 [‎291r] (84/154)

PROPOSAL FOR AN EXPEDITION TO SANNIKOFF LAND.
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a northern temperate climate, the fact still remains that no imaginable redistribu
tions of seas and sea-currents would account for the growth of even temperate-zone
trees and shrubs in those high latitudes, especially when those latitudes were
occupied by a large arctic continent. More fossil material from the highest
latitudes is therefore required now, even much more than it was required when
the remarkable conclusion of Oswald Heer as regards Tertiary vegetation became
first known. The great question raised by Heer—and there is no other question of
equal importance in the whole domain of Tertiary and Quaternary geology—will
remain unsettled so long as we have not more fossil Tertiary plants from very high
latitudes, in order to determine the true character of the sub-arctic Tertiary flora.
The latest discoveries relative to the changes of position of the Earth’s axis of
rotation have given new support to the hypothesis mentioned by Baron Toll,
according to which hypothesis the pole may have been situated in Tertiary times
several degrees southwards from its present position. The curve which the pole
has described within the last few years is—we now know—a spiral, not a closed
circle. But, with all that, the distribution of the tertiary vegetation round the
pole seems to indicate that the climate was wanner in all directions from the pole.
A change in the position of the axis may thus be insufficient to explain the facts
relative to the Tertiary flora when these become known in their totality. We
must therefore know the Tertiary flora of high latitudes in its entirety; otherwise we
are bound to float in incertitude amidst the different hypotheses.
A third set of facts which have lately been discovered, especially due to the
latest investigations in the southern hemisphere, is the astounding similarity of
the Tertiary flora all over the surface of the globe. These researches are far yet
from being complete, but already they seem to indicate that during the Tertiary
age the distinctions between the different zones of the Earth were not so sharp as
they are now; the climate on the surface of the globe seems to have been more
equal than it is at the present time. If this be true, if the sharp climatic dis
tinctions which we now see between the different zones did not exist in Tertiary
times to the same extent and with the same sharpness as they do exist now, a
great question arises; namely, was not that relative uniformity of climate due to
a different composition of the atmosphere of our globe ? And this question, of
highest importance for geology, can only be solved by getting considerable quanti
ties of fossil Tertiary plants from both the arctic and antarctic regions.
And fourth, a new hypothesis, which assumes, indeed, a change in the com
position of the atmosphere, has been brought to the front by the great physicist,
Arrhenius, and has been further developed by one of the greatest authorities
on the recent geological history of the globe. Prof. Chamberlin, of Ghicago-
According to this hypothesis, the immense change in the climate of the globe,
which took place between the Tertiary times and the Glacial period, may have had
its cause in an increase of percentage of carbonic acid in our atmosphere. I he
volcanic eruptions which took place on an immense scale at the close of the
Tertiary age in America, and in the arctic regions (and I will add, in the antarctic
regions as well, and on the immense Vitim plateau and its border-ridges in Siberia),
may have thrown into our atmosphere considerable quantities of carbonic acid; and
Arrhenius has shown that even a very small addition of this gas to the atmosphere
would considerably reduce its transparency for the heat-rays of the sun. Besides,,
one is naturally brought to the suggestion that the gases newly discovered in our
atmosphere may also have varied in quantity at different geological epochs, the
more so, as one of them, helium, is known to appear in a relatively great proportion
in the waters of mineral springs, such springs being closely connected with volcanic
outbreaks. In short, the variable constitution of the atmosphere may have been