106 MUSCULAR WORK 
when turning the wheel of the centrifugal machine the gross efficiency was 
14.5 to 16.6 per cent ° and the net efficiency, 24.1 to 27.9 per cent. 6 Reach 
also noticed an alteration in the net efficiency incidental to increased velocity, 
the net efficiency having a tendency to decrease as the velocity increased. 
Another summary of the results of the Zuntz school has been made by 
Loewy, c who finds that the energy consumption for 1 kilogrammeter of work 
in lifting the body when walking up an inclined plane was from 2.190 to 3.770 
kilogrammeters with a dog, and with a horse 2.912 kilogrammeters. With a 
man, when the inclination of the path was 6.5 per cent, the energy consump- 
tion was 3.165 kilogrammeters; with an inclination of from 23 to 30.5 per 
cent, it was 2.831 kilogrammeters, and from 30.7 to 62 per cent, 3.559 kilo- 
grammeters. He states that the values varied inversely with the body-weight, 
changing considerably according to the size of the individual, but contends 
that for every kilogrammeter of work in the elevation of the body there is 
required on the average 3 kilogrammeters of energy output. In computing 
the work done in turning the wheel of an ergostat, he takes as an average 
value 4 to 4.3 kilogrammeters of energy after a long training in the experiments 
of Heinemann, while the experiments of Katzenstein, in which the subjects 
had less experience, show 5.5 to 7.1 kilogrammeters of energy. Loewy, like 
other writers of the Zuntz school, indicates that for walking up an inclined 
plane the net efficiency would be on the average 33.33 per cent, while for turn- 
ing a brake ergometer, the net efficiency would be 24 to 25 per cent for well- 
trained men, and considerably less than 20 per cent for untrained men. 
In connection with the studies on mountain-climbing or raising the body 
to a given distance, the interesting experiments of Jaquet and Svenson on 
fat persons should be cited. d Employing the special pedal apparatus of Jaquet 
described by H. Christ, 6 Jaquet and Svenson made experiments on two fat 
individuals, one weighing 118 kilograms and the other 93.7 kilograms. The 
increased oxygen consumption per kilogrammeter during work was with the 
first subject, 4.67 c.c. per minute; with the second, three different experi- 
ments gave 1.722, 2.1, and 1.79 c.c. per minute, respectively. These values 
are considerably above those found by Katzenstein, f who found on four 
different individuals, 1.187, 1.244, 1.435, and 1.504 c.c. 
In their extensive researches upon the influence of muscular work on 
metabolism, Sonden and Tigerstedt," using the large Stockholm respiration 
chamber, determined the carbon-dioxide output of individuals while turning 
the Gartner ergostat. For purposes of comparison they computed the carbon 
dioxide per kilogrammeter of work done from the data of preceding experi- 
ments. The results have been tabulated and given on page 19 of this report. 
Reach h computed from the carbon-dioxide values found by Sonden 
and Tigerstedt that the gross efficiency of the body would be 17.3 per cent, 
and the net efficiency, 27.4 per cent. 
Using a Gartner ergostat inside the large respiration chamber in the 
Hygienic Institute in Berlin, Rubner * made an experiment on a man who 
o Reach, loc. cit., p. 1074. & Reach, loc. cit., p. 1082. 
c Loewy, Oppenheimer's Handbuch der Biochemie, Jena, 1911, 4, (1), p. 274. 
d Jaquet and Svenson, Zeitschr. f. klin. Med., 1900, 41, p. 1. 
e Christ, Deutsch. Archiv f. klin. Med., 1894, 53, p. 102. 
/ Katzenstein, Pfliiger's Archiv, 1891, 49, p. 368. 
Sonden and Tigerstedt, Skand. Archiv f. Physiol., 1895, 6, p. 187. 
A Reach, he. cit., p. 1053. 
i Rubner, Sitzungsber. k. Preuss. Akad. Wissensch., 1910, 16, p. 316. 
