Page 231 - Lokmanya Tilak Samagra (khand 2)

18 SAMAGRA TILAK- 2 • THE ARCTIC HOME
altitude and the existence of oceanic and aerial currents, carry-
ing and diffusing the heat of the equatorial region to the other
parts of the globe, have been found to produce different climates
in countries having the same latitude. The Gulf Stream is a
notable instance of such oceanic currents and had it not been
for this stream the climate in the North-West of Europe would
have been quite different from what it is at present. Again if
the masses of land and water be differently distributed from what
they are at present, there is every reason to suppose that differ-
ent climatic conditions will prevail on the surface of the globe
from those which we now experience, as such a distribution
would materially alter the course of oceanic and aerial currents
going from the equator to the Poles. Therefore, in the early
geological ages, when the Alps were low and the Himalayas
not yet upheaved and when Asia and Africa were represented
only by a group of islands we need not be surprised if, from
geological evidence of fossil fauna and flora, we find that an
equable and uniform climate prevailed over the whole surface
of the globe as the result of these geographical conditions. In
Mesozoic and Cainozoic times this state of things appears to
have gradually changed. But though the climate in the Secon-
dary and the Tertiary era was not probably as remarkably uni-
form as in the Primary, yet there is clear geological evidence to
show that until the close of the Pliocene period in the Tertiary
era the climate was not yet differentiated into zones and there
were then no hot and cold extremes as at present. The close
of the Pliocene and the whole of the Pliestocene period was mark-
ed by violent changes of climate bringing on what is called the
Glacial and Inter-Glacial epochs. But it is now conclusively
established that before the advent of this period a luxuriant
forest vegetation, which can only grow and exist at present in the
tropical or temperate climate, flourished in the high latitude of
Spitzbergen, where the sun goes below the horizon from
November till March, thus showing that a warm climate prevail-
ed in the Arctic regions in those days.
It was in the Quaternary or the Pleistocene period that
the mild climate of these regions underwent sudden alterations
producing what is called the Glacial period. The limits of this
Glacial period may not so exactly coincide with those of the
Pleistocene as to enable us to say that they were mathematically