86 ENERGY TRANSFORMATIONS DURING HORIZONTAL WALKING. 



of May 14 the subject walked at the rate of 146.4 meters per minute, 

 with a heat-output of 0.953 gram-calorie per horizontal kilogrammeter. 



In the four following periods the subject ran, although the speed 

 per minute was approximately the same as that in the walking period. 

 Nevertheless, the average heat-output per unit of work was materially 

 less, i. e., 0.812 gram-calorie. 



It is thus apparent that the velocity had a very considerable influ- 

 ence upon the heat per unit of work when the subject was walking. 

 This confirms the earlier contention of Durig and his associates that the 

 heat required to move 1 kilogram 1 meter increases with the speed. 

 Furthermore, the method of progression, i. e., walking or running, had 

 likewise a very considerable influence on the heat per unit of work. 

 Both of these factors require subsequent elaboration. 



COMPARISON OF THE HEAT PER UNIT OF WORK AS COMPUTED FROM DIFFERENT BASE-LINES. 



The last three columns of table 14 permit the comparison of the heat 

 per unit of work, i. e., per horizontal kilogrammeter, as computed 

 from the three base-lines. Instead of using the individual values hi 

 table 14, however, this comparison can better be made by using only 

 the average figures for the several groups presented in the foregoing 

 discussion on the influence of velocity. To find exactly the differ- 

 ences due to the selection of the base-line, we have therefore brought 

 together in table 15 a general average for all of the experiments without 

 food, both walking and running. The walking experiments are 

 divided into three groups, according to the speed at which the subject 

 walked. Thus we have 57 periods when the subject walked at a slow 

 rate ranging from 56 to 93.3 meters and averaging 71.5 meters, 6 periods 

 with a medium speed averaging 106.3 meters per minute, and 7 periods 

 with a high speed averaging 144.1 meters per minute. During the 

 running experiments, the speed averaged 147.5 meters per minute. 

 The values showing the heat-output per unit of work done, using the 

 Benedict and Cathcart basal value (lying I), are given in column 6, 

 those for which the basal value of April 18, 1914, was employed (lying II) 

 in column c, and those calculated from the basal value found with the 

 subject standing in the relaxed position are given in column d. 



With the large amounts of heat involved in the walking experiments 

 the relatively slight differences appearing in these three base-lines 

 should not have a very great effect. It is obvious, moreover, that the 

 greater the amount of work done in walking, the less will be the per- 

 centage change due to the selection of the base-line. Thus we note that 

 the heat per unit of work done at the slow speed is lower when the 

 standing basal value is employed than it is when the lying value II 

 (that of April 18, 1914) is used, the difference between the two averages 

 being approximately 6 per cent. With the increase in the work 

 involved in walking at the moderate speed, the difference due to the 

 selection of the basal value becomes considerably less, i. e., 3 per cent, 



