Mans Mechanical Efficiency in Work Performance. 401 



taken in the first hour. The " accountancy " of measurements has followed 

 exactly the same rigid plan, and the data now published have been 

 carefully scrutinised again on exactly similar lines. The subject's efficiency, 

 as calculated from his own results, arid in agreement with those already 

 considered, is such that the subtraction necessary to remove the moiety of 

 heat production associated with external work performance is 3"85 K. 

 Removing these fractions the " cost of movement " is left, and in this case it 

 represents that cost at definitely different rates of movement. 



E. J. Briscoe, 1912. " Stripped weight " 55'8 kgrm. E = 3-85. 



Date. 



V. 



Eevs. 

 per minute. 



K. 



Work. 



H. 



Heat 

 production. 



EK. 



Subtraction. 



» = H-EK. 

 Besidue. 



1912. 

 (1) May 24.... 

 *(2) May 14.... 

 *(3) May 17.... 

 *(4) May 20.... 

 *(5) May 22.... 

 (6) May 7.... 

 April 25 . 

 May 21.... 

 fMarch 28. 

 fMarch 29. 



40 



60 



72 

 74 

 80 



97(?) 

 98 (?) 



21 



13 



26 



34 -5 



42 -5 



49 



16 



73 



10 



11 



159 

 167 

 212 

 244 

 286 

 341 

 222 

 456 

 291 

 316 



81 

 50 

 100 

 133 

 164 

 189 

 62 

 281 

 40 

 42 



79 

 117 

 112 

 111 

 122 

 152 

 160 

 175 

 251 

 274 



* Data in British Association Beport, 1912, p. 289, numbered there as 2, 3, 4, 5. 



t The query by the side of the revolution rate will be understood to refer to the difficulty of 

 maintaining these fast rates in a perfectly uniform way, there always being a tendency for 

 groups of faster to succeed groups of slower movements. 



These Briscoe data have been given in the same form as all the data up to 

 the present, and may be compared at once with them, but for the purposes 

 of the later part of this paper they are now changed in form. Kalories per 

 hour are now changed into Small calories per second, revolutions per minute 

 into " per second," and doubling this revolution rate, so taking account of the 

 two complete leg-movements associated with each revolution of the cycle 

 pedals, they are presented as " strides per second." 



Another change may also be noticed from this point onwards, namely, the 

 large number of apparently significant figures in which the rates of move- 

 ment are expressed (thus, 2-667 per sec), but this method has proved of 

 value, in so far as these figures are submitted to speculative arrangement 

 always in the same definite form in which they are given. 



