000 



THE APPLICATIONS OF PHYSICAL FORCES. [BOOK v. 



communicating the oscillating motion of the pendulum on one side to 

 the transmitting apparatus, and on the other to the indicator. Since 

 these two apparatus work separately, one of the cranks is detached 

 when the other receives its reciprocating motion, and this crank 

 moves the style on the surface of the transmitter where the message 

 is placed, and in the following manner : 



The crank is itself articulated to the lever that carries the style. 

 In the successive oscillations it makes this lever and the tracing -point 

 describe a series of circular arcs, parallel to each other and to the 

 surface of the cylindrical sheet of metal to which is applied the 

 metallized paper of the message (Fig. 392). When the pendulum 

 makes a complete oscillation, the moving style crosses from left to 



FIG. 3'.1. Facsimile of a drawing reproduced by CaseJli's pautelegniph. 



right and passes over the whole breadth of the message. At the 

 end of this motion the style comes against a stopper, and the 

 shock turns the rod which carries it, so that it is raised and separated 

 from the paper throughout the whole length of the following 

 oscillation. The apparatus thus only works during one-half of the 

 motion of the pendulum. The reason of this arrangement arises 

 from its having been shown by experience that the effects produced 

 by the oscillations in the opposite direction are not identical, 

 out in order to use 'these oscillations the transmitting apparatus is 

 double, only the mechanism is reversed, and it is the same for the 

 indicators. The result is that no time is lost, as two messages may 

 one be received and the other sent at the same time. 



Ah essential condition for the satisfactory working of Caselli's 

 pantelegraph is that there should be a perfect synchronism between 



