he piecework of thousands of factory operatives, and
upon millions of deaths and births in a score of different countries. It
takes account of three chief climatic conditions--temperature, humidity,
and variability. It also takes account of mental as well as physical
ability. Underneath it is a map of the distribution of civilization
on the basis of the opinion of fifty authorities in fifteen different
countries. The similarity of the two maps is so striking that there can
be little question that today the distribution of civilization agrees
closely with the distribution of climatic energy. When Egypt, Babylonia,
Greece, and Rome were at the height of their power this agreement was
presumably the same, for the storm belt which now gives variability
and hence energy to the thickly shaded regions in our two maps then
apparently lay farther south. It is generally considered that no race
has been more closely dependent upon physical environment than were the
Indians. Why, then, did the energizing effect of climate apparently have
less effect upon them than upon the other great races? Why were not
the most advanced Indian tribes found in the same places where white
civilization is today most advanced? Climatic changes might in part
account for the difference, but, although such changes apparently
took place on a large scale in earlier times, there is no evidence of
anything except minor fluctuations since the days of the first white
settlements. Racial inheritance likewise may account for some of the
differences among the various tribes, but it was probably not the chief
factor. That factor was apparently the condition of agriculture among
people who had neither iron tools nor beasts of burden. Civilization
has never made much progress except when there has been a permanent
cultivation of the ground. It has been said that "the history of
agriculture is the history of man in his most primitive and most
permanent aspect." If we examine the achievements and manner of life of
the Indians in relation to the effect of climate upon agriculture and
human energy, as well as in relation to the more obvious features
of topography and vegetation, we shall understand why the people of
aboriginal America in one part of the continent differed so greatly from
those in another part. In the far north the state of the inhabitants
today is scarcely different from what it was in the days of Columbus.
Then, as now, the Eskimos had practically no po