RESEARCHES BY OTHER INVESTIGATORS. 



exchange. Four subjects were used and the basal metabolism and the 

 metabolism during horizontal walking were determined. The grade 

 of the treadmill was of moderate pitch, varying from approximately 

 10 to 13 per cent. As computed from the respiratory quotients, the 

 heat-output was 5.69 to 7.33 calories per kilogrammeter, with efficien- 

 cies of 31.9 to 41.1 per cent. The great variations in the results of 

 Katzenstein are in no small part due to the wide differences in his 

 estimations of the oxygen consumption per horizontal kilogrammeter, 

 which ranged from 0.0858 c. c. for his subject Zimm to 0.1682 c. c. for 

 his subject Krzywy, and also to the fact that the relatively low grade 

 of the treadmill did not produce a large amount of work. 



In the same year Gruber 1 made a study of the effect of training in 

 the ascent of approximately 80 meters to the Munster tower outside 

 of Berne. The experiments were made after a midday meal, and the 

 carbon-dioxide production alone was determined by a gravimetric 

 method. The results are primarily of interest as implying increased 

 efficiency following training. 



Schumburg and Zuntz, 2 in a study of the effects of high altitudes, 

 report a series of experiments with Zuntz walking on a treadmill in 

 Berlin at a grade of 31 per cent and a speed of 24 meters per minute, 

 in which the average oxygen consumption per kilogrammeter of work 

 done was 1.77 c. c., or an efficiency of 27 per cent. With Schumburg 

 as the subject, the oxygen consumption was 1.73 c. c., with an efficiency 

 of 28 per cent. Later, these two men, when walking up a grade of 31 

 per cent on Monte Rosa, found their efficiencies to be 20.9 and 23.2 

 per cent. 



A. and J. Loewy and L. Zuntz, 3 preliminary to their expedition to 

 Monte Rosa, made a series of measurements on a treadmill in Berlin 

 at grades of about 23.0, 30.5, and 36.6 per cent. The energy produc- 

 tion per kilogrammeter of grade work, after the resting value and the 

 value for the horizontal component had been deducted, varied from 

 6.74 to 8.07 calories per kilogrammeter for A. L., 6.53 to 7.30 calories 

 for J. L., and 6.41 to 7.32 calories for L. Z., with efficiencies from 29 

 to 36.5 per cent. The lowest efficiency was found with A. L. and 

 the highest with L. Z. 



In the expedition on Monte Rosa made by these investigators, in 

 walking up grades of 26 to 33 per cent at Col d'Olen with an elevation 

 of 2,840 meters, and at Capanna Gnifetti, with an elevation of 3,620 

 meters, the metabolism per kilogrammeter of work due to the grade 

 walking was as follows: For A. L., 8.13 and 9.11 calories per kilograms 

 meter; for J. L., 8.23 and 8.99 calories; for L. Z., 8.77 and 8.41 calories. 

 The efficiencies were: For A. L., 28.8 per cent at Col d'Olen, and 25.7 



r, Zeitschr. f. Biol., 1891, 28, p. 466. 

 2 Schumburg and Zuntz, Arch. f. d. ges. Physiol., 1896, 63, p. 461. 

 3 A. and J. Loewy and L. Zuntz, Arch. f. d. ges. Physiol., 1897, 66, p. 477. 



