FRESH AIR AND EFFICIENCY 285 



I have referred to the fact that the chamber experi- 

 ments proved that relief is experienced when the air 

 of the chamber is set in motion by fans. Doubtless 

 this relief, even when the foul air has a wet-bulb 

 temperature of 8o-85 F., results from the displace- 

 ment it brings about of the hot air, at a wet-bulb tem- 

 perature of 98 F., which is in contact with the skin 

 and enmeshed in the clothing immediately against 

 the skin. 



In 1906 Dr. James Kerr reported to the London 

 County Council (as the Education Authority for the 

 County of London) upon the relation of the class-room 

 atmosphere to the working efficiency of school chil- 

 dren. The following tests were adopted : The number 

 of simple addition and subtraction sums that could be 

 worked in five minutes; and, in order to assess correct 

 judgment, the estimation of an angle copied from a 

 blackboard. Numerous observations were made by 

 Drs. Thomas, Stevenson, Hogarth, and Brincker in 

 which the four chief air factors, viz. temperature, 

 humidity, movement of air, and carbon dioxide, were 

 associated in every combination and their effects 

 studied. It was found that " in every case where 

 boys were working under good air conditions the 

 results showed a distinct improvement at the end of 

 the session, whereas when these air conditions were 

 acknowledged to be bad, the results were always in- 

 ferior at the end of the session".' Again, "if the 

 results of similar mental tests set before and after a 

 school session to a class of average children show a 

 falling-off, or even an absence of improvement, in 

 mental ftlertness and accuracy, it is just to conclude 

 that some deteriorating influence has been at work. 

 By methods of exclusion this was shown, in these 

 observations, to be the atmospheric conditions". The 

 observations appeared to warrant the following further 



