172 SUBMARINE CABLE LAYING ANT KEPAIE1NG-. 



are then packed and screwed up, making water-tight joints with 

 the cables. 



The box is placed at low-water mark so that tha cables are 

 never uncovered by water. The pipes, which are of wrought 

 iron with screwed socket joints and connectors, are continued 

 from the box up the beach in trench to the interior of the cable 

 house, where they are turned upwards and surmounted by a 

 water tank. 



The leads (of good gutta-percha core, say in duplicate for 

 each cable) are bunched together, connected to a draw wire at 

 the cable-house end and drawn through the pi pea to the box. 

 In a similar manner the earth wires are drawn in a separate 

 pipe. After testing to see that they have not been damaged 



Fig. 85. — Cable Junction Box. 



in drawing in, the line leads are jointed to the respective cables 

 and the earth leads to the sheathings. It is advisable to keep 

 the earths distinct as far as the cable house for testing purpose?, 

 although this is not necessary for signalling. The line joints 

 are made as ordinary cable core joints, and the earth joints are 

 soldered. After carefully coiling up any slack in the box the 

 cover is bolted down on the gasket, making a water-tight joint, 

 and water is then put into the tank in the cable house, filling 

 up the pipes and box entirely and the tank to about two-thirds 

 of its capacity. Air is allowed to escape from tha box before 

 screwing down or by filling the pipe slowly. If good joints 

 have been made the level of water in the tank will not fall, 

 except very slowly by evaporation. This system is convenient 

 from the point of view of repairs. Should a f=iult appear close 

 in, the beach lead can be cut at low water and tested, and it is 



