THE EFFECT OF CLIMATE AND WEATHER 319 



CLIMATIC DIFFERENCES OF RACE 



Up to this point our data have appHed only to the 

 European branch of the white race. But do other races 

 react Hke the white man? What little exact evidence is yet 

 available suggests distinct differences in the cHmatic optima 

 of different races or of the same race when living in different 

 chmates, but it also suggests that these differences are 

 shght. In Japan the optimum appears to be ahiiost the 

 same as in the United States. At Osaka for example, the 

 126,000 deaths from 19 13 to 19 17 indicate an optimum of 

 approximately 66°f. and 70 to 80 per cent relative humidity. 

 Among Cuban cigar-makers in Florida the best work is 

 done when the temperature averages from 65° to 70° which 

 is somewhat higher than among the factory workers of New 

 England. The conditions among Negroes in the United 

 States are illustrated in Figure 7 which is hke Figure 3 

 except that it is based on 167,000 colored people instead of 

 921,000 white people. Although the cities were the same in 

 both cases, the colored people are mainly found in the 

 more southerly of them so that Figure 7 represents a some- 

 what more southerly region as w^ell as a more tropical race 

 than Figure 3. Nevertheless the two figures are almost 

 identical. The only important difference is that the opti- 

 mum temperature for the Negroes is about 4° higher than for 

 the whites, and the optimum relative humidity also a trifle 

 higher. 



Fortunately we are not limited to the American Negro 

 for our knowledge as to the climatic optimum of tropical 

 people. In Java the Dutch have gathered exact statistics 

 for a race that has lived close to the equator for many 

 centuries. Of course there are no low temperatures even in 

 the towns at greatest altitudes, but so far as they go the 

 Javanese data agree closely with those for whites and 

 Negroes. Although the dark-skinned Javanese have lived 

 close to the equator for so long, their optimum temper- 

 ature appears to be near 70°f. or only about 5° above that of 

 the white race; and their optimum humidity does not seem to 

 differ materially from that of the Europeans. Morever, what 

 little evidence we have suggests that mild changes of tem- 

 perature are just as stimulating to tropical people as to the 



