162 SECTIONAL ADDRESSES. 
mechanical and nervous. Neither can the argument be applied to very 
long races, where—as we shall see below—other types of exhaustion 
set in. 
Comparison of Men and Women; Swimming and Running. 
There are certain characteristics of these curves which are of interest. 
In the first place those for men and women are almost precisely similar. 
For a given time of swimming the maximum speed for a woman appears 
throughout the curves, to be almost exactly 84 to 85 per cent. of that for 
aman. The curve relating oxygen requirement to speed, in the case of 
swimming, is not known from experiment, nor are the maximum oxygen 
debts and the maximum oxygen intakes known for women with any 
certainty. It would be very interesting to determine them, were volun- 
teers forthcoming. If we assume what is roughly true, that the energy 
expenditure rises approximately as the square of the speed, we may con- 
clude that a woman swimming is able to exert, per kilogram of body 
weight, about 72 per cent. of the power expended by aman. Women are 
well adapted to swimming: their skill in swimming is presumably just as 
great as that of men; the difference in the maximum speed for any given 
time can be a matter only of the amount of power available. 
In running, the same typeof comparison may be made, though here not 
over the same range of times. For anything but the shortest races the 
maximum speed of a woman is almost precisely 79 per cent. of that of a 
man running for the same time. For very short times, 5 to 10 seconds, 
the ratio is greater, namely 84 per cent. Here again there would seem 
little reason to attribute the difference of speed, at any rate for the longer 
races, to anything but a difference in the maximum amount of power 
expendible over the period in question. Assuming again, as an approxi- 
mate means of calculation, that the energy used per minute varies as the 
square of the speed, we see that a woman running is able to liberate in a 
given time only about 62 per cent. of the energy expendible by a man of ~ 
the same weight. It is probable that this ratio between men and women, 
as determined by swimming and by running respectively, is really the 
same in either case, and that the apparent difference depends upon an 
inexactness in the simple laws we have assumed for the variation of 
energy expended with speed. It would seem fair to take the mean of 
these two values, 67 per cent.—that is, about two-thirds—as the ratio of 
the amount of energy expendible by a woman in a given time as com- 
pared with that by a man of the same weight. It would be of great 
interest—and quite simple—to test this deduction by direct experiment 
on women athletes. 
Men and Women Jumping. 
A further interesting comparison between men and women may be 
found in the records of high jumps and long jumps. The world’s record 
long jump for a man is 25°5 ft., for a woman 16-9 ft. The high jump 
records are respectively 6°61 ft. and 5 ft. At first sight, when compared 
with running, these records for women seem extraordinarily poor: the 
high jump is only 75-5 per cent., the long jump only 66 per cent., of 
that for men. Sucha conclusion, however, rests upon a misunderstanding, 
almost like that which makes many people believe that if a man could 
