12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



The melikeron is an instrument which responds sluggishly and is 

 rather difficult to manipulate. Furthermore, temperatures computed 

 from its readings depend upon the Stefan radiation constant and upon 

 the assumption that the radiation measured is similar to that of a 

 black body. For these reasons the melikeron-computed temperatures 

 should not be given equal weight with those measured by the thermo- 

 element, and the i° difference noted may not be entirely real. There 

 are, however, three factors each of which tends to make the melikeron 

 skin temperature higher than the thermoelement values on the skin, 

 namely : 



(i) Due to the ridges and roughness of the skin surface, the 

 thermoelement touches the outer and cooler parts of the ridges, 

 whereas the melikeron views both ridges and hollows. 



(2) As shown by Bazett and McGlone (loc. cit., p. 433) the tem- 

 perature I mm. below the surface of the skin may be as much as 

 .6° C. higher than the surface temperature. Since the outer layer of 

 skin is scaly and comparatively dry, it may well transmit a small but 

 appreciable amount of radiation coming from the moist and warmer 

 layer below. 



(3) Each measurement with the melikeron requires several min- 

 utes. The involuntary, psychological reaction resulting from so long 

 an exposure of skin near the instrument aperture may tend to raise 

 the temperature of the exposed skin. 



. Our conclusion then is that the 1° higher temperatures on the skin 

 resulting in the mean from the melikeron observations would probably 

 be reduced to about ^° if all experimental error were removed. Due 

 to the combination of the three tendencies just mentioned, tempera- 

 tures at least several tenths of a degree higher than those measured 

 by the thermoelement appear to result from the melikeron readings 

 on the skin. 



