204 SUBMARINE CABLE LAYING AND REPAIRING, 



grapnel rope. The plungers are pointed below, and when 

 weighted by the pressure of the cable force their way through a 

 rubber disc on to a brass contact plate. The grapnel rope con- 

 taining the electrical core for use with this grapnel is patented 

 by Messrs. Trott and Hamiltoa, and, as no swivels are used, the 

 rope is specially designed with a view to the prevention of 

 kinking consequent upon the grapnel turning over on the 

 bottom and twisting it. The system, which is worked with the 

 Anderson and Kennelly indicator, has been used by Captain 

 S. Trott and Mr. H. Kingsford on board the "Minia," the Anglo- 

 American Company's repairing steamer, since the year 1883, 

 with great success. The illustration (Fig. 115) shows the 

 position of the contact buttons and insulated plate in this 

 grapnel ; and it may be mentioned here that, should a prong 



Fig. 115. — Trott and Ivingsford's Indicating Grapnel. 



become fractured or broken off, the insulation of the contact 

 plate will be partially destroyed and a current set up which 

 can be distinguished on board, as it is weaker than that caused 

 by hooking cables. Notwithstanding the great ingenuity of 

 this grapnel, there is the disadvantage of requiring a special 

 grapnel rope both on account of the core and the fact that no 

 swivels can be used, and it is not possible with this rope to 

 have it made up in sections of convenient lengths, nor to use a 

 length of chain in front of grapnel to bear the chaiing on the 

 bottom. 



The devices described above for easily and quickly replacing 

 the broken prongs of a centipede grapnel by new ones have 

 served the purpose of limiting the very large number of com- 

 plete grapnels that, otherwise, a ship would be compelled to 

 carry, and have also effected a very considerable saving in time. 

 There is still, however, something left to be desired. When a 



