276 ON THE TRACK OF THE MAIL-COACH 



miles long, which has crept out from the land — the 

 wondrous mirror contrives to reflect with fidelity 

 signals from Crookhaven, or, similarly, at that office, 

 signals from the lighthouse. These latter, too, are 

 despatched from a chamber perched more than a 

 hundred feet in the air, on the summit of a sea- 

 girt rock. Over the Fastnet it is the rule, rather 

 than the exception, for the Atlantic waves to send at 

 least clouds of spray, and, as often as not, to break in 

 great billowy masses. 



After this rough-and-ready, but not inaccurate, 

 exposition, I must add a technical word or two, 

 warranted by what one of the inventors himself tells 

 me, for the satisfaction of those who may demand a 

 more exact explanation ; although I admit that 

 without the aid of a diagram it is difficult to set 

 forth the matter with absolute clearness. 



The two wires which are led down the front of the 

 rock into the sea may be compared to the merry- 

 thought of a fowl, the mirror being intermediate at 

 the bony apex. One wire and its ' centipede ' may be 

 considered as an earth-Avire, the other as a cable-wire, 

 although actually it is an earth-wire too. 



Each time the Crookhaven battery is connected to 

 the main cable, and a signal is thereby sent, it 

 necessarily follows that the main cable's two earth- 

 plates — viz., the ' mushroom ' submerged in the 

 vicinity of the Fastnet, and that in the water at 

 Galley Cove, close to the Crookhaven post-office — 

 become charged (together with the cable), either 



