264 SUBBIAEIXE CABLE LAYING AND REPAIRING. 



tools, spare jointing materials, galvanometer mirrors and sus- 

 pensions, &c. {see Fig. 155). The batteries, •which may amount 

 to two or three hundred cells, are all ranged in racks underneath 

 the testing-table, and the connections brought to commutatora 

 by which the battery power can be easily changed as required. 

 There is also a library, and a comfortable lounge along one 

 side of the room, this sanctum of the electrician being 

 generally a cosy little place, where are spent some of the 

 many hours passed at sea while steaming from one position to 

 another. In bad weather it is a welcome retreat, from whence 

 you can, reclining, 



" With sidelong eye look out upon the scene," 



though it may be in no such satisfied frame of mind as "Words- 

 worth's dreaming man. 



It will be understood that on starting the coiling of cable 

 picked up, the end was left sticking up at the side of the tank, 

 so as to be accessible for connecting on an insulated leading 

 wire to the testing-room. This insulated wire remains so con- 

 nected until the first cut takes place, when it is shifted on to 

 the new end. In the testing-room the end of this wire is con-, 

 nected to the testing terminal during the ship's tests, or is^ 

 shifted over to a terminal on the speaking connections when it 

 is desired to communicate with the shore. Also in the periods 

 of time during which it is arranged for the shore to test, the 

 end is either freed or earthed by the ship as required. 



A set of testing and speaking connections, such as fitted in 

 the testing-room of a repairing steamer, is shown in Fig. 156. 

 The apparatus and arrangement of connections vary somewhat 

 in difierent ships, but are generally arranged in such a manner 

 that by simply changing one or two plugs the cable can be tested 

 by bridge or deflection methods. The galvanometers used are 

 either the marine astatic galvanometer of Lord Kelvin, with 

 the damping device, or the Sullivan suspended coil galvanometer. 

 In the set of connections here shown, the cable is connected to 

 the terminal S for speaking to the shore, and to the terminal X 

 for testing, the commutator plugs P P and the plug B being put 

 in for bridge test, and the plug D being put in (the others being 

 removed) for deflection test. In addition to the instruments 

 shown, there are high resistances and standard cell for the 



