102 WORLD-POWER AND EVOLUTION 



kept open as much as possible and the temperature averaged 

 below 60° most of the time; (II) moderately warm rooms having 

 no ventilation except by means of windows; (III) moderately 

 warm rooms provided with artificial ventilation by means of fans. 

 When we divide these rooms into three groups according to tem- 

 perature, as has been done by Miss Baker in her report on the 

 experiment, we get the following result: 



Evidently the warm rooms were much worse than the cooler rooms. 

 In fact, the amount of sickness in group C was almost twice as 

 great as in the rooms that averaged 66.6°, that is, group B. The 

 cooler rooms, group A, were not quite so favorable as the middle 

 group (B), but children are clearly much better off in such rooms 

 than in the ones averaging 69° or more. It is striking to see that 

 the best health is found in the group of rooms where the tempera- 

 ture comes nearest to the ideal, that is to 64". 



Another comparison of these rooms is still more significant. 

 Miss Baker groups them as follows: 



The rooms of group I had an average temperature below 60°, 

 and were apparently a little too cool for children dressed in the 



