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THE POPULAR SCIENCE MONTHLY. 



the Seine ; the regulator at the Hotel de Ville automatically sends a 

 current into twenty relays at precisely one hundred seconds before the 

 end of each hour, and thus cuts these wires off from their ordinary 

 telegraphic duty and places them in the circuits of the different mairies. 

 Then, at twelve seconds before the end of the hour, the regulator 

 sends another current into the circuit of the mairies ; this current 

 is stopped precisely at the end of the hour. At each mairie the clock 

 automatically shuts off the wire from the telegraph and connects it 



