BODY TEMPERATURE. 245 



date, using the Du Bois linear measurement as the basis. The 

 photographic method, as commonly employed, uses the factor 5.02. 

 With Squad A, the average factor for the first measurement on Sep- 

 tember 29 would be 5.05. For November 24 it would be 5.03 and 

 for February 2, 5.17. With Squad B the average factor would be, 

 for January 5, 5.19, and for January 27, 5.15. 



Since the factor of 5.02, originally derived, was obtained from rather 

 a large number of individuals (20 in all) of grossly varying surface 

 conditions, it is perhaps somewhat surprising that with the more 

 homogeneous material supplied by the subjects in tables 18 and 19, the 

 same average factor is not obtained. Two important points should be 

 considered in this connection, first, that the profile photographs with 

 both Squads A and B were made with artificial light in the laboratory 

 at night, by hanging a large sheet on a frame, and placing behind it 

 an M-type Cooper-Hewitt lamp. This method of illumination was 

 by no means so satisfactory as the daylight method used for the 

 earlier series in which the photographic method was developed and a 

 white sheet was hung before a window. Secondly, the pictures were 

 taken principally to show the general physical contour of these men 

 and not with the special care necessary for their use in accurate photo- 

 graphic measurements, a precaution which should have been taken. 

 Finally, when it is considered that these 12 men were photographed 

 in the nude a few minutes before they entered the respiration chamber 

 at night, and that they were pecuharly sensitive to cold, it will be 

 seen that the photographing was inevitably hastened too much for 

 the best results. Consequently, care was not always taken to place the 

 metric scale exactly opposite the backbone of the subject. Further- 

 more, it was found necessary to focus the camera on the pedestal upon 

 which the men stood and then take all the photographs without re- 

 focusing for each subject. We beUeve that these considerations suffi- 

 ciently explain the variations from the average 5.02 noted in the 

 development of the formula by the photographic method. 



As a check upon the Du Bois measurements, however, the photo- 

 graphic measurements are very helpful. Attention should be called 

 to the almost uniform agreement in the Du Bois measurements with 

 Squad A for November 24 and February 2. It is a gratifying veri- 

 fication of these measurements to note that they can be made with a 

 squad of 12 men some 10 weeks apart and still show such uniform 

 agreement with each other. It will be remembered that there was 

 a negligible difference in weight of these men on November 24 and 

 February 2. 



BODY TEMPERATURE. 



The sensation of cold, which was noted throughout a good part of 

 the research by practically all of the men, made a study of body tem- 

 perature of special significance. Each morning, prior to the measure- 



