32 2 



HUMAN BIOLOGY 



such as give to the northeastern United States, northwestern 

 Europe and Japan a constant but moderate variabihty from 

 day to day at all seasons. 



180 150 120 90 60 SO 30 CO 90 120 150 180 



150 120 



Fig. 8. World Map of Climatic Energy. 

 (From Huntington's Business Geography, ed. 2, John Wiley & Sons, Inc.) 



It cannot be too strongly emphasized that Figure 8 is a 

 purely chmatic map showing the degree to which the chmate 

 probably departs from the optimum for health and activity. 

 Nevertheless this map of chmatic energy is almost identical 

 with maps of both health and civihzation. The interpretation 

 of this threefold agreement is clear in the hght of our 

 previous discussion of hmits and optima. The chmatic map 

 must be the foundation, for neither health nor civihzation 

 can possibly produce any appreciable effect upon the dis- 

 tribution of chmate. Hence it appears that in the world today 

 the primary control of the distribution of health and civihza- 

 tion is chmate. The way the matter works appears to be as 

 foHows : 



The more nearly the chmate approaches the optimum the 

 greater the degree of health and energy. The greater the 

 degree of energy, the more hkely people are to make advances 

 in civihzation. But an advance in civihzation means improve- 

 ment in health by reason of new knowledge, and improved 

 health in turn helps toward still further advance in civihza- 



