PRINCIPLES OF VENTILATION 319 



These figures indicate that the external temperature requir- 

 ing the least metabolism to maintain the normal bodily tem- 

 perature of this man dressed as he was dressed, was about 

 60F. It is now generally accepted that there is one certain 

 temperature which is best adapted to, i.e., most agreeable to 

 each individual when that individual is dressed with a certain 

 weight of clothing and is in repose. 



The experience of stockmen shows that stock exercising 

 but little, as is usually the case with dairy cows and with 

 beeves and hogs being fattened for the market, thrive best 

 when the temperature is moderate. Extremes of tem- 

 perature, either high or low, reduce the flow of milk in the 

 dairy cow and tend to prevent the fattening of the beef- 

 cattle and hogs. In each case, nourishment taken by the 

 animal is expended in effecting the control of bodily tem- 

 perature. We also know that work horses are not able to do 

 so much work in extreme temperatures as in moderate tem- 

 peratures, although the best temperature for the horse at hard 

 work is considerably lower than when at rest. 



350. The Ideal Temperature of Indoor Air. The best 

 temperature for indoor air depends largely upon the occupa- 

 tion and dress of the occupants. The proper temperature for 

 a gymnasium or a factory would certainly not be the proper 

 temperature for a schoolroom or a church. Even the best tem- 

 perature for a schoolroom or a church might prove to be too 

 low a temperature for the home, owing to the fact that most 

 people are likely to be more warmly clad when at school or 

 church than when at home. 



As will later be shown, the relative humidity of the air in the 

 room also largely determines the proper temperature. Rea- 

 sonably moist air at 65F. is as comfortable as very dry air at 

 70. The temperature usually demanded by Americans is 

 several degrees higher than that preferred by the English and 

 Germans. Our own physical condition also largely determines 

 the most agreeable temperature. In the morning when our 

 vitality is highest, we are comfortably warm at a temperature 



