280 



THE HUMAN MOTOR 



FIG 17? 



Frontal face of the handle. 



a pm, 



1. Efforts Exerted Perpendicularly to the Handles. One of the 

 handles of the 



truck is sawn on 

 the line S-S' at 

 0-30 m. from 

 the free extre- 

 mity. The fixed 

 part, I, then has 

 attached to its 

 lateral sides two 

 metal plates, 



AB and A'B', which hold the detached part and are jointed by 

 OO', which works without friction (fig. 172). Further, 

 on the front face of the handle, 

 an oval spring, R, is fixed, and 

 is screwed to the vertical ends 

 of two metal angle plates, 

 Q and Q', fixed on the same 

 face (fig. 173), whilst on the 

 opposite side two similar metal 

 angle plates are fixed, whose 

 vertical edges support, the one 

 a Marey's tympan and the other 

 a rod m, which works the mem- 

 brane (fig. 174). In reality the 

 connexion of the rod m with the 

 membrane of the tympan is more 

 complicated and indirect, and 

 includes a lever which allows 

 modifications of the oscillations 



of the membrane of the tympan. For a similar rotation of the 

 handle round the axis OO', the mem- 

 brane could receive an easily-regulated 

 displacement and the tympan trans- 

 mit movements of greater or less 

 amplitude. It is sufficient to fit one 

 only of the handles, with these attach- 

 ments the effort of the man being 

 practically symmetrical. 



2. Efforts Exerted in the Direction of 

 the Handles. For this second meas- 

 urement, one handle is made cylindri- 

 cal and enveloped in a metal sleeve, M, 

 carrying an angle bracket, H opposite 

 a second angle bracket, H' the brackets 

 being connected by an oval spring, R. 

 On the opposite side a tympan and rod 



system, as described in the preceding paragraph, is fixed. 



F.o. 173. 



Front face with the oval spring R. 



Front Face 



Fin. 174. 



