Physical Problems in Study of Conditions for Health 33 



by A. McAdie (Rand McNally), should be consulted for additional 

 references and for admirable resumes of recent meteorological progress. 

 Inspiration for many pieces of research will also be found in these volumes. 



Summary 



The object of this paper is to attract more workers to a very important 

 field. The need for further investigation is great, and emphasis is laid 

 upon the necessity of eliminating the frequent errors in certain experi- 

 ments which are concerned with the gain or loss of heat. Examples and 

 advice are given, particularly with reference to the proper discrimination 

 between conflicting factors, to the treatment of humidity questions, and 

 to the determination of the characteristics of hygroscopic surfaces. 



The following list of nine problems requiring attention, are suggested 

 as leading to researches which could be undertaken in any laboratory, 

 and from which "results" would be almost certain. Comments and 

 some details in regard to the general object and the possible procedure 

 are given in each case. 



(1) The variation of aqueous vapour pressure from characteristic 

 hygroscopic substances with changing external temperature. 



(2) The variation of the internal temperature with the difference in 

 aqueous vapour pressure between that of the surface and the surrounding 

 air, for small volumes of hygroscopic materials. 



(3) The influence of the irregularity of a hygroscopic surface upon 

 its vapour pressure. 



(4) Simple methods of measuring total heat emission. 



(5) The influence of turbulence and incident radiation upon instru- 

 ments for measuring the rate of heat loss from bodies. 



(6) The improvement of the physical apparatus employed in the 

 calorimeter experiments on metabolism. 



(7) The applications of the atmometer. 



(8) The influence of atmospheric conditions upon the electrical state 

 of a surface. 



(9) The development of electrical hygrometers for precision work. 



McGiLL University. 



