450 THE INSCRIPTIONS AT COPAN. 
These two regions are about 4,500 kilometers apart in round numbers, or 
about soo kilometers more than the big trees of California are from the region 
of the Old Empire. 
Penck, the leading German authority on climate, agrees with Hunting- 
ton, on independent lines of research, that the present zone of aridity in the 
Northern Hemisphere formerly lay much nearer the Equator, which, if so, 
would have brought to the region of the Old Empire a somewhat drier 
climate than it now enjoys: 
“All this leads us to assume that the area of extreme aridity in Africa once lay 
much nearer the Equator than it does to-day, exactly as was the casein both Americas, 
and guided again by the phenomena of the Great Basin, we may fix this period in 
the Ice Age. The Great Ice Age presents itself, then, neither . . . nor as a period 
of excessive humidity over the whole earth, but as a period during which the cli- 
matic belts were shifted into lower latitudes.’”! 
OLD EMPIRE NEW EMPIRE 
EARLY MIDDLE GREAT TRANSITIONAL 
PERIOD PERIOD PERIOD PERIOD 
650 
700 
ST 
------------ ---------- ------------ ------=----1750 

Fic. 71.— Diagram showing supposed variation in rainfall in the Maya area from 500 B. Cc. to 1000 A. D., 
after Huntington. 
The striking agreements mentioned above between the climatic curve 
obtained from the Sequoia washingtoniana and the writer’s correlation of 
Maya and Christian chronology appear clearly in figure 71, which shows 
the variation in rainfall in California for 1,500 years, during the last 500 
years before Christ and the first millennium after Christ, as established by the 
varying thicknesses of the rings of 450 Sequoia washingtoniana.? Hunting- 
ton gives the following general explanation of this curve: 
1Penck, 1914, p. 290. Other recent investigations in this field will be found in the bibliography under the 
following titles: Arctowski, 1910-1913, vol. XLII, pp. 270-282, 481-495; vol. XLIv, pp. 598-606, 745-760; vol. xLv, 
pp. 117-131; Brooks, 1916, pp. 249-255; Helland-Hansen and Nansen, 1916, pp. 1-341; and Huntington, 1918, 
pp. 483-491. 
* Huntington, 1917, p. 158. 
