795 
E. Situ reported in his publication, of which mention has already 
been made, that equal muscular work has a greater influence on the 
respiratory exchange in winter than in summer; his experimentation, 
however, does not, in our opinion, vouch for this conclusion. 
Our experiments were made in the months of March, April, May, 
June, and July 1912. 
We proceeded as follows. The experimentation took place in the 
afternoon, at the same hour, shortly before dinner, in order to 
give scope to the presumable influence of close heat. We were 
sitting on a bicycle without wheels, placed on a stand. A rotatory 
disk had been fixed at the place of the large chain-wheel. Round 
it a steel brake-band could be tightened or slackened to render the 
work more severe or lighter (Fig. 2). 
Spring-balance 
Adjusting screw 
Rotating disk .----- 
Fig. 2. 
The upper part of the band was connected with a spring-balance 
by means of a long wire. When the adjusting screw was tightened - 
the friction increased and the band was taken along by the disk, 
while the pedalling continued, which caused the springbalance to 
register a higher figure. The increase, however, was not such as to 
alter the statie moment materially. Both the bracket-spindle of the 
bicycle and the rim of the disk were continually being oiled during 
the experiment. | 
The pedalling rate was regulated by a metronome, ticking 133 
times per minute. 
Before the subjects, both skilled cyclists, started pedalling, a deter- 
mination was made, while they were quietly seated on the bicycle; 
which involved only a very light statie muscular activity. In the 
subsequent period of the experiment the subject was pedalling for 
a quarter of an hour, while breathing freely and after this for five 
minutes, while breathing through the valves. Only then the estima- 
tion was performed, while the subject went on ,pedalling; we then 
could reasonably presume that a condition of equilibrium between 
internal and external gas-exchange had been established. 
