274 



METABOLISM DURING WALKING. 



a. m., the body-temperature decreased rapidly, the fall amounting to 

 1.14 C. in 12 minutes, or 0.09 C. per minute. Unless the technique 

 was at fault, which has not been revealed by a careful inspection of the 

 records, this change in temperature of the body in cooling is by far the 

 greatest and most rapid we have found. A possible explanation, but one 

 for which our records give no data, is that the subject stood without 

 the usual blanket covering. In this case, with the thin, short-sleeved, 

 and short-legged athletic suit worn by the man, the radiation would 

 be greatly increased. The curve would thus indicate that the un- 

 restricted liberation of heat from the body can be as rapid as the sudden 

 production of heat following the beginning of muscular exercise. 



38.80 



38.60 



36.4O 



SB.20 



saoo 



37.60 

 37.60 

 37.40 

 37.20 

 37.00 

 f&BO 

 30.60 



Fio. 36. Typical body-temperature curves of E. D. B., with subject standing, 



and walking on an incline. (Values per minute.) 

 1, subject sitting; 2, standing; 3, walking on an incline. Black points, records 



during experimental periods; open circles, records between periods. 



Figure 37 (a grouping of curves for February 18 and 22, March 23, 

 and April 8) gives four contrasting curves showing typical changes in 

 body-temperature. The curves for the experiments with a 40 per cent 

 grade (February 18 and 22) have already been shown in curves D and 

 B in figure 35. These are in strong contrast to the curves for the 

 experiments of April 8 and March 23, in which the grades were 10 per 

 cent and the speed of walking 36 and 62 meters per minute, respectively. 

 The lowest curve of the four (that for April 8, when the smallest amount 

 of work was done) shows that the rise in temperature was not large 

 and that the fall between the periods was slight. Apparently, at the 

 close of the last period, the rise in temperature was approaching a limit. 

 The curve for the other experiment with a 10 per cent grade (March 23) 

 indicates a more rapid increase in temperature, with a more decided 

 fall between the periods. There is no evidence that the rise had reached 

 its limit when the experiment ceased. The two curves with steeper 

 grade (40 per cent) show similar characteristics, but in greater degree. 



