Heat-production Associated ivith Muscular Work. Ill 



Group A. — Heat-production = K a W 4/3 

 Group B.— I = K 6 W 2 / 3 



Group C— „ = K C WV 3 



Group D. — „ = Kd 



Clearly these results demonstrate the decreasing influence of the weight 

 upon the heat-production as increasing values are given to the performance of 

 mechanical work. To put the facts in simple terms, without attempting any 

 further analysis, the weight becomes less and less of a handicap as the rate of 

 work is increased, until at the final level reached in these experiments the 

 burden of the day is the same for all. This does not say that it may be borne 

 equally well by all. Small bodies embroiled in an equal heat-production are 

 obviously at a disadvantage, since, although their surfaces and thus their means 

 of heat loss are relatively large in proportion to their weights, yet they are 

 actually smaller than the larger surfaces surrounding the greater masses. 

 Thus higher temperatures might be thought of as impending in their case. 



It will be of interest to continue these experiments, and that, too, at 

 higher levels of work-performance. It would, for example, be well to 

 determine whether this was the end or not of this process in the removal 'of 

 the handicap of the weight. It would be remarkable if at some higher level 

 of work-performance the weight should be developed into a positive advantage, 

 and the relationship be capable of expression as follows : — 



Heat-production = KW"". 



Leaving this, however, for the present alone, it is legitimate to inquire into 

 the possible causation of these results as they stand. Thus, when dealing with 

 the nature of the process responsible for the appearance of the weight in 

 these results, it will be well at once to focus attention on this query : Is 

 any importance to be assigned to the observation at the lowest level of 

 work-performance, in which the weight made its appearance in the greater 

 dignity of the form of W 4/3 ? For, if not, it would be simple to consider 

 that all of these expressions are variations from the well known expression 

 for the heat-production of rest (heat-production = KW 2 ' 3 ), in which the 

 importance of the surface, W 2 / 3 , is gradually removed with the increasing 

 elimination of the activity of that special nervous mechanism that regulates 

 heat-production when heat-loss is the dominant circumstance. But, if, on 

 the other hand, attention must be paid to it — and why not ? — then some 

 consideration must be given to some influence of the weight or of the mass 

 of the body other than as a value which determines the extent of its 

 surface. This may conceivably be dealt with under two headings. 



Thus, on the one hand, it may be thought that the weight, per se, makes 



