266 ILLINOIS ACADEMY OF SCIENCE 



that of the white man lies at 65° and 80 per cent relative 

 humidity. 



These two points are significant first in that our rooms 

 are all too warm and dry being at 70°F. and 30 per cent 

 instead of 65°F and 80 per cent. Thel negro who came 

 to America from moist tropical Africa differs from the 

 white man who came from somewhat drier and much 

 cooler western Europe. 



Variability of temperature is stimulating to the codlin 

 moth pupae (see Figure 4 B). The amount of respira- 

 tory diseases among children in school rooms with win- 

 dow ventilation and accordingly more variable tempera- 

 tures is only about half as geat as with fan ventilation. 

 Furthermore Figure 4 A is taken from the work of Mr. 

 Huntington and shows that variable temperatures in- 

 crease efficiency. The manual laborer's efficiency is in- 

 creased either by a rise or fall from day to day. Effi- 

 ciency of brainworkers, especially students, is increased 

 by a fall of temperature from day to day and decreased 

 by a rise in temperature from day to day. And it seems 

 that we have done well to choose the time of year for 

 their most important examinations when the temperature 

 is rising from day to day, it apparently being our pur- 

 pose to eliminate as many students as possible. It is 

 altogether possible that our schools should begin in the 

 middle of August and close considerably earlier than 

 they do. 



Huntington has made a careful study of death-rate in 

 relation to climate and weather and has compared busi- 

 ness, school attendance, etc., with health or the death- 

 rate curve inverted. Figure 5, curves A and B, show 

 this relation for the entire eastern United States for 

 1880-1910. The curves for Great Britian are similar. 

 Curves B and C of Figure 5 show the death-rate in Chi- 

 cago and damage by chinch bugs in Illinois. During the 

 period from 1885 to 1895 the death-rate in Chicago rose 

 high. These were troublous times with strikes, bloody 

 anarchists, and HajTuarket riots at the close of the 

 eighties, due to the presence of a democratic president in 

 Washington and certain wild-eyed agitators in Chicago, 



