24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



SUMMARY OF RESULTS. 



The concrete results of these experiments are brietiy summarized : 

 (i) The radiation from the skin and clothing is approximately 

 that of a " black body " or perfect radiator. 



(2) Skin temperatures computed from melikeron radiation mea- 

 surements are about 1° C. higher than skin temperatures measured 

 directly with the thermoelement. This is not true on clothing or 

 calorimeters. Apparently the melikeron sees deeper into the pores of 

 the skin. 



(3) A cloth-covered, vertical, cylindrical calorimeter at body tem- 

 perature loses in still air 60% by radiation, 40% by convection. A 

 similar horizontal calorimeter loses 54% by radiation, 46% by con- 

 vection. The human body convection loss is probably similar to this, 

 that is, the convection loss is roughly one third less than the radia- 

 tion loss, in still air and normal room temperatures. 



(4) Increasing air motion rapidly decreases the percentage radia- 

 tion loss and increases the convectional. With the vertical calorimeter : 



Air motion % radiation loss 



60 



7S ft. per mill. 41 



130 ft. per mill. 35 



190 ft. per min. 25 



(5) Total body radiation similarly decreases with air motion: 



Air motion Radiation loss (mean for lo subjects) 



o to 50 ft. per mill. 30.7 large cal. per sq. m. per hour 



50 to 100 29.3 



100 to 150 25.7 



180 to 250 23.2 



(6) Increase in room teinperature (which also means increase in 

 wall temperature) ])roduces a progressive lowering of radiation loss. 

 The ratio 



Radiation loss 

 Basal metabolism 

 decreases with increase of room and wall temperature: 



Radiation loss 



Room temp. Basal metabolism 



^ ,, T J 21°. 3 .80 (mean of 10 subjects) 



1 24.1 .75 (mean of 10 subjects) 



(22.1 .84 (mean of 3 subjects) 



Table J J 24.5 .74 (mean of 4 subjects) 



1 25.6 .66 (mean of 3 subjects) 



(7) Keeping room and wall temperatures unchanged, the tem- 



l^erature of skin and clothing decreases with increasing air motion, 



