CHAPTER IV. 



THE CABLE SHIP ON REPAIRS. 



Speaking Apparatus. — The position of a fault having been 

 determined by a selection of tests, the cable ship proceeds to 

 this position, first leaving instructions upon what day and 

 time the terminal stations are to commence keeping watch for 

 her. When the insulation of the land-line between the office 

 and cable-house is perfect, watch is usually kept in the office 

 on the siphon recorder instrument, this being most convenient ; 

 but if it is at all low the ship will not be satisfied with testing 

 through it, and watch has to be kept at the cable-house, where 

 the shore-end of the cable is landed. In such cases a set of 

 speaking apparatus, precisely similar to that on board ship, 

 and usually kept at the cable-house, is connected up, as in 

 Fig. 93. A battery of Leclanche cells, in the proportion of 

 one cell, at most, to 60 miles of cable, is joined up to the 

 sending key S, as shown ; the conductor or line of the cable is 

 connected through the mirror instrument to one side of this 

 key, the earth side of the same being connected to the sheath- 

 ing of the cable. 



It is usual to fit up a small terminal board in the cable-house 

 and bring the cables and their earths to it, where they can be 

 joined to the terminals of the land-lines leading to the office. 

 It is therefore a simple matter, when watch for the ship is to be 

 kept at the cable-house, to disconnect the required cable and 

 its earth from the pair of land-line terminals to which they are 

 joined, and connect them to the speaking apparatus as shown. 



