MOTION. 
Tasie 10. 
In the following table we find the proportion 
between the duration of the slep and the 
time of the leg resting and swinging 
during very diversified paces. 
Duration of Duration of Duration of 
Step. Standing. Swinging. 
“a “” “ 
. 0.344 0.341 0.347 
: 0.376 0.400 0.352 
: 0.429 0.484 0.374 
0.523 0.570 0.476 
0.742 0.817 0.667 
These experiments prove that the time in 
which the leg is swinging is least in the quickest 
, and is equal to half the whole time of 
_ oscillation of the leg ; that it increases in pro- 
portion as the step becomes slower; that, con- 
sequently, that division of time which the 
_ Swinging leg occupies in describing its entire 
curve is increased by one-half of the entire 
_ portion of time, and more in proportion as the 
_ pace becomes slower. ‘This gives rise to an- 
_ other range of experiments. which have been 
_ made by the Messrs. Weber with the same 
_ design, of which the following table is the 
~ result.* 
; TaBLeE 11. 
_ Experiments on the time in which the leg 
stands on the ground, with various degrees 
of velocity in walking. 
Duration | Length Duration 
of of of the Leg 
Step. Step. Velocity. | resting. 
“ q m. “a 
0.317 0.820 2.587 0.317 
0.430 0.741 1.721 0.513 
0.463 0.712 1.537 0.504 
0.582 0.621 1.067 0.692 
0.660 0.562 0.851 0.782 
Whence we deduce the following comparison 
between the duration of the leg standing and 
that of its swinging. 
Duration Duration Duration 
of of of 
Step. Standing. Swinging. 
0.317 0.317 0.317 
0.430 0.513 0.347 
0.463 0.504 0.422 
0.582 0.694 0°472 
0.660 0.782 0.538 
The number of steps which a person can take 
‘in a given time in walking depends, first, on 
_ the length of the leg, which, governed by the 
_ laws of the pendulum, swings from behind 
_ * In these experiments the footsteps were taken 
on the ball only. 
467 
forwards: secondly, on the earlier or later in- 
terruption which the leg experiences in its are 
of oscillation by being placed on the ground. 
When the hinder leg has quitted the ground, it 
swings forward by its own gravity, in conse- 
quence of its freedom of motion in the ilio- 
femoral articulation and its oblique position ; 
and, in order that the body may be supported, 
it must, at least, move so far forwards that the 
foot may arrive at a position vertically under 
the head of the femur; for in that direction 
the leg not only supports the body with least 
effort, but it is also in that position that it can 
most easily avoid any impediment in its path 
by transferring the point of support to any por- 
tion of the sole of the foot, particularly if the 
latter be turned outwards, which gives a greater 
security than when it is directed parallel to the 
line of motion. The weight of the swinging 
leg and the velocity of the trunk serve to give the 
impulse by which the foot attains a position 
vertical to the head of the thigh bone; but as 
the latter, according to the laws of the pendu- 
lum, requires, in the quickest walking, a given 
time to attain that position, or half its entire 
curve of oscillation, it follows that every person 
has a certain measure for his steps, and a cer- 
tain number of steps in a given time which in 
his natural gait in walking he cannot exceed. 
We can easily ascertain the time it requires to 
accomplish the quickest step in walking, which 
is equal to the half vibration of the leg made 
with relaxed muscles. In order to make the 
steps follow each other in much slower succes- 
sion, the foot isnot placed on the ground when 
it arrives in the perpendicular position, or the 
half oscillation from behind forwards as in the 
rapid pace, but we plant it on the ground 
somewhat later when the foot has described 
more than half the curve of vibration. From 
these principles we conclude that the man in 
Jig. 255 walks much faster than that in fig. 256; 
in fact the former makes steps 27.559 in. in 
length, whereas in the latter the steps are barely 
23.622 in. in length; and whereas the first 
makes a step in 0”.35, the second takes 0.422 
for a step, so that the velocity of fig. 255 is 
nearly double that of fig. 256. These figures 
are represented as walking on the toes, as if the 
foot always touched the ground in the same 
position, and their steps are shorter than when 
the entire sole is brought into action. Fig. 255 
shows the greatest step which it is possible to 
make with the toes. The steps are shortest in 
fig. 257, in which the difference of the heights 
of the centre of gravity, compared with that of 
Jig. 255, may be easily seen.* 
In, figs. 258, 259, and 260, the legs are of 
* These figures, with the others upon the same 
lan, reduced to ith the natural size, are drawn 
in accordance with the principles on which the 
theories of walking, running, and leaping are 
based. They are taken in the various instants of 
a step as seen through a revolving disc, con- 
structed upon the principles of the stroboscope in- 
vented by Dr. Faraday, and modified so as to 
apply to these purposes by Stampher.t These 
+ Vide Poggendorft’s Ann. vol. 22. p. 600. 
2 W<2 
