ELECTRIC TELEGRAPHS. 



417 



them very close parallel lines at a uniform distance apart, both styles 

 being in permanent connection with the line-wire. The current is fur- 

 nished by the battery (P) at the sending station. When the style is on 

 a conducting portion of the paper M, the current takes the course of 

 least resistance (A BCD), no sensible portion of it going to the other 

 station. On the otber hand, when the style is on the non-conducting 



Fig. 17. 



Caselli's Telegraph. 



ink in winch the dispatch is written, the circuit ABCD is broken, and 

 the current travels through the line-wire. At this moment the style 

 on the sheet R is in exactly the same position as that on the sheet M, 

 by reason of the synchronism of the pendulums, and a blue line will 



VOL. III. 21 



