33 



THE POPULAR SCIENCE MONTHLY. 



ready to receive the time-signals. The electrical working of the appa- 

 ratus which accomplishes this will be understood by reference to Fig. 

 8.* Under normal conditions, the current from the observatory passes 



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 J 



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H 

 P 

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H 

 O 



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directly through the chronopher, and out at the galvanometer G', to 

 the tower-clock at the Houses of Parliament, "Westminster. This clock 

 has a gravity escapement, and a metallic compensating pendulum, 

 very similar to the pendulum of the Sidereal Standard, already de- 

 scribed, and runs with a rate of less than one second per week. The 



* The small figures 1, 2, 3, 4, to the right of Fig. 8 and to the left of Fig. 9, show the 

 connection between the wires. 



