FRENCH STATE TELEGRAPH. 



further multiplied, by giving to the regulator itself a motion 

 round its centre, so that it might at will assume the horizontal or 

 vertical position, or might take an intermediate direction. 



In transferring this system of signals to the electric telegraph, 

 the regulator is supposed to he placed permanently horizontal, 

 and the two indicators to be capable of receiving any of the eight 

 positions here explained. 



183. The telegraph contrived by M. Breguet, to exhibit such a 

 system of signals, consists, like the double needle telegraph, of 

 two distinct and perfectly similar instruments, one for each of the 

 indicators. They are mounted side by side with their accessories 

 in the same case, at a distance apart sufficient to allow the indi- 

 cators to revolve without mutual obstruction, and sufficiently near 

 each other to allow the same person to work both at the same 

 time with his right and left hand. 



Each instrument consists of an indicating apparatus and a com- 

 mutator. 



If s and s' be two stations, between which dispatches are trans- 

 mitted, the commutator at s moves the indicator at s 7 , and the 

 commutator at s' moves the indicator at s. 



A view of the indicating apparatus is given in fig. 70. The 

 two indicators are fixed upon axes placed in the same horizontal 



Fig. 70. 



line upon the dial. These axes, passing , through the dial, carry 

 behind it two escapement wheels, which are controlled by two 

 anchors, as described in 151. These anchors are moved by the 

 armatures of two electro-magnets, from which they receive vibra- 

 tions, like those of a pendulum. The escapement wheels are 

 impelled by the force of two main-springs, transmitted to them by 

 two similar trains of clock-work. 



15 



