WEATHER AND CLIMATE 135 



The benumbing effects of the cold of the higher latitudes, 

 and the enervating effects of heat and moisture in tropical 

 countries, may be named as sufficient cause for the failure 

 of the peoples of these regions to keep pace with the other 

 parts of the world in the arts and activities of civilized life. 

 However, the enterprise of the present day has been able to 

 master adverse climatic conditions. This is strikingly ex- 

 hibited in the Panama Zone, Cuba, and the Philippines, as 

 controlled by the United States, and in portions of tropical 

 Africa under the enlightened rule of European nations. 



Aside from the discomforts of extreme heat or cold, exces- 

 sive moisture or dryness, and dangers from exposure to 

 weather changes, it is not easy to establish definite relation- 

 ships between weather conditions and the health of people- 

 generally. A breeze, springing up in a hot day in summer 

 when there has been no air stirring, does for large numbers 

 of people what starting an electric fan does for the persons in 

 a room whose hot stagnant air has become oppressive and 

 benumbing. Though the temperature of the air may remain 

 the same, perspiration vaporizes more rapidly,- there is a 

 lower body temperature, a lessened sense of discomfort 

 and of nervous irritation, and an invigoration that bespeaks 

 less waste of nerve energy. Certain diseases have been 

 prevalent and often are epidemic at certain seasons of the 

 year. But knowledge of the nature of infectious diseases, 

 and of the ways of their prevention, lessens the likelihood of 

 any such relationship being maintained. 



It is a common experience, however, that the presence of 

 too much moisture in the air on a hot summer day so interferes 

 with the rapid vaporization of the perspiration from the body 

 that great discomfort follows. Heat prostrations, especially 

 in sea board cities, are frequently the direct result of the body 

 being unable to get rid of its own heat sufficiently fast through 

 vaporization of perspiration. Overcrowded and poorly venti- 



