Page:Popular Science Monthly Volume 3.djvu/431

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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 furnished 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 (ABCD), no sensible portion of it going to the other station. On the other 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