th.]

The earth is an inseparable whole. Each country or sea is physically and
historically intelligible only as a portion of that whole. Currents and
wind-systems of the oceans modify the climate of the nearby continents,
and direct the first daring navigations of their peoples. The
alternating monsoons of the Indian Ocean guided Arab merchantmen from
ancient times back and forth between the Red Sea and the Malabar coast
of India.[33] The Equatorial Current and the northeast trade-wind
carried the timid ships of Columbus across the Atlantic to America. The
Gulf Stream and the prevailing westerlies later gave English vessels the
advantage on the return voyage. Europe is a part of the Atlantic coast.
This is a fact so significant that the North Atlantic has become a
European sea. The United States also is a part of the Atlantic coast:
this is the dominant fact of American history. China forms a section of
the Pacific rim. This is the fact back of the geographic distribution of
Chinese emigration to Annam, Tonkin, Siam, Malacca, the Philippines,
East Indies, Borneo, Australia, Hawaiian Islands, the Pacific Coast
States, British Columbia, the Alaskan coast southward from Bristol Bay
in Bering Sea, Ecuador and Peru.

As the earth is one, so is humanity. Its unity of species points to some
degree of communication through a long prehistoric past. Universal
history is not entitled to the name unless it embraces all parts of the
earth and all peoples, whether savage or civilized. To fill the gaps in
the written record it must turn to ethnology and geography, which by
tracing the distribution and movements of primitive peoples can often
reconstruct the most important features of their history.

Anthropo-geographic problems are never simple. They must all be viewed
in the long perspective of evolution and the historical past. They
require allowance for the dominance of different geographic factors at
different periods, and for a possible range of geographic influences
wide as the earth itself. In the investigator they call for pains-taking
analysis and, above all, an open mind.

NOTES TO CHAPTER I

[1] George Adam Smith, Historical Geography of the Holy Land, pp.
149-157. New York, 1897.

[2] A.P. Brigham, Geographic Influences in American History, Chap. I.
Boston, 1903.

[3] R.H. Whitbeck, Geographic Influences in the Development of New
Jersey, _Journal of Geography_, Vol. V, No. 6. January, 1908.

[4] Hans Helmolt,