398 



Prof. J. S. Macdonald. 



It will be seen that the respective ratios of the number 37 to the 

 numbers 132, 135, 142 and 169 are the individual values of F the 

 efficiency, and realised that the individual values of E (the reciprocal 

 of the " efficiency in work performance ") are contained in the last column 

 in the factors 3 - 57, 3*65, 3 - 84, and 4'57. The values of these factors 

 expressed in terms of the " stripped weights " of the different subjects are : — 



It is of advantage to display these figures in this way prior to making the 

 necessary corrections, since the method of correction is dependent on the 

 accuracy of separate experiments in which measurements were made of the 

 power absorbed by a motor (1) when driving the cycle against the particular 

 brake used in the experiments, and (2), always in the same series of observa- 

 tions, against rope-brakes arranged to entail the same power-absorption. In 

 these experiments it was accurately ascertained that in the neighbourhood 

 of the experimental rate, the power-absorption, and therefore the work done, 

 in the cycling experiments varied with the square of the rate. Aberrations 

 from the standard rate therefore must be regarded as seriously affecting the 

 amount of work done. 



Examining the aberrations in rate shown in the tabulated data (Groups B 

 and D, loc. cit), it is found that, with the exception of Bennett, the subjects 

 deviated sensibly and in much the same proportion from this rate in 

 Group D, but maintained it steadily in Group B. The explanation is 

 simple : conducted by the same rhythmical light signal, they were 

 dependent on the clock from which the signal was worked (electrical 

 contact), except Bennett, who preferred to be guided by the tick of a clock 

 inside the calorimeter. These aberrations have been corrected for, in every 

 single datum in the tabulated data, on the precise basis of variation with 

 the square of the rate, and the average correction so obtained entails the 

 following alterations in the statement of work-performance : — 



(1) Kemp 



(2) Eae 



(3) Bennett .. 



(4) Armstrong 



E 

 E 

 E 

 E 



67 W-°-"\ 

 67 W- -™ 

 67 W-°- 715 , 

 67 W-° >711 . 



Actual work, K. 



Name. 



Actual increment, 

 dK. 



K„ Group B. 



K 2) Group D. 



(1) Kemp 



(2) Eae 



(3) Bennett .., 



(4) Armstrong 



18 -87 



19 -00 

 19-00 

 19 00 



56 -56 

 56 -76 



55 59 



56 -67 



37 "69 

 37 -76 



36 -59 



37 "67 



