218 SUBHAEINE CABLE LAYING AND REPAIRING. 



jection8 in the ocean bed where the depth increases very sud- 

 denly, as, for instance, near the Nicobar Islands, in the Indian 

 Ocean. The wires so broken leave the strain to be borne 

 by the core, which it is seldom able to support without rup- 

 ture, or damage is caused by the ends of the broken wires 

 pressing into the core. It has been suggested from time to 

 time to do without the iron sheathing wires altogether, and 

 depend alone upon a hemp covering ; but although there are 

 many points in favour of this construction, and some cables 

 without sheathing wires have been successfully laid, there has 



Fig. 127.— Raising Cables in 800 Fathoms. 



been found some difficulty in sinking such cables during laying, 

 and grappling for them afterwards, whiie considerable shrinkage 

 occurs, with detriment to the core. The experience gained on 

 this subject has been given in Chapter II. 



To afford some idea of the depth from which cables are 

 picked up, a sketch Is given in Fig. 127, showing the relative 

 size of a cable ship, 240ft. long, picking up cable in 800 

 fathoms. Repairs are more often in depths under 1,000 

 fathoms; but not unfrequently cable is raised from 2,500 

 fathoms, or over three times the relative depth shown in the 

 sketch. 



