WALKING. 119 



ference of the pubis towards the right, the depression will 

 express a deviation of this poiut towards the left. 



The experiment gives the curve O P It (fig. 22) for the 

 tracing of the horizontal oscillations. It is first to be ob- 

 served that the number of these oscillations is only half that 

 of those which take place in the vertical direction ; so that 

 the body is carried towards the right side at the moment of 

 the maximum of elevation, which corresponds witli the middle 

 of the pressure on the right foot, and towards the left at the 

 middle of the pressure on the left foot. This lateral sway- 

 ing of the trunk is the consequence of the alternate passage 

 of the body into a position sensibly vertical over each foot. 



If we would give an idea of the true trajectory of the pubis 

 under the influence of these two orders of oscillations com- 

 bined \\ith forward movement, we must construct a solid 

 figure. With an iron wire bent in different directions, we 

 may illustrate very clearly this trajectory. Fig. 23 is intended 

 to represent the perspective view of this twisted iron wire ; 

 but we can scarcely expect the reader to comprehend clearly 

 this mode of representation. 



Fie. 2.T. Attempt to illustrate, Viy means of n, metallic wire, the sinnons 

 trajectory passed through by the pubis. To understand the sketch of 

 this solid t gnre, \ve must supp e the wire to ho close to the observer 

 at its left hand extremity, while it is removed from him at the riirlit ex- 

 tremity. The amplitude of the oscillations has been g.-catly exaggerated 

 to render them more intelligible. 



In short, according to the formula of Mous. Carlet, the 

 trajectory of the pubis may be inscribed in a hollow half- 

 cylinder, with its concave portion upwards, at the base of 



