ELECTRIC CLOCKS 



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a golden slide, by which the electric circuit had been completed, and the current is 

 cut off; the pendulum is thus able to mako its return -vibration by mere gravity. It 

 starts to repeat the above operations also by gravity ; but, ere it completes the arc, 

 the rod pushes back the slide, and again completes the electric circuit, and gives rise 

 to a second impulse, and so on. A small amount of magnetic attraction is sufficient 

 to supply the necessary amount of maintaining power. One pair of zinc-copper, 

 buried in the moist earth, has been found ample. 



In an ordinary clock, the train is carried by a weight or by a spring, and the time 

 is regulated by the pendulum. In Bain's the time is regulated and the train is driven 



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by the pendulum. The rod hangs within a crutch in the usual way ; the crutch carries 

 pallets of a particular kind, acting in a scape-wheel ; and, from the latter, the motion 

 VOL. II. 



