

SUBMARINE TELEGRAPHY 245 



It is extremely difficult to obtain accurate statistics as to the 

 number of miles of cables laid, lost, and now at work. Many 

 are in the hands of distant Governments, who give no informa- 

 tion ; and some are so frequently under repair that it is difficult 

 to know in what category to place them. In 1862, in Mr. 

 Jenkin's report to the Jurors of the Great Exhibition, 5,345 

 statute miles of cable, and 9,456 miles of gutta-percha wire, 

 were said to be in working order ; 9,406 miles of cable were 

 classed as having been successful for some time, but not then 

 working ; 557 miles were classed as total failures. These 

 numbers were avowedly mere approximations. 



Mr. Francis Gisborne published statistics in 1865, in which 

 he put the numbers for working and non-working cables at 

 5,066 and 11,261 statute miles respectively. Dr. Eussell gave 

 6,842, and 9,407, as the length of cables at work and abandoned. 

 Since then 3,754 miles have been added to the successful list by 

 the Atlantic expedition. The Gutta-Percha Company claim 

 now to have supplied insulated core for 12,100 miles of cable, 

 which are still at work. Whatever the actual numbers are, it is 

 incontestable that a large proportion of lines laid have failed 

 from time to time. The Red Sea, and Batavia-Singapore Cables, 

 upwards of 4,000 statute miles long, failed from their want of 

 weight and strength ; they rusted rapidly, and could not be 

 repaired when faults appeared, or when they chafed through ; 

 or rather the expense of the continual repairs was such that 

 they were abandoned, perhaps somewhat prematurely. The 

 failures of some deep-sea cables have in all probability been due 

 to lightning. An unaccountable apathy has in many cases led 

 to the neglect or actual removal of the lightning dischargers 

 attached to submarine lines, and the writer has seen neglected 

 dischargers with points fused and burnt away, proving that the 

 line had been struck repeatedly. Other failures have been 

 attributed to the tautness of the cable when laid, to friction at 

 the bottom, to volcanic action, etc. ; but not much is known 

 about these causes, which are rather hypothetical than proved. 

 Neglected faults have certainly, in some cases, been much en- 

 larged, by the use of more and more powerful batteries, added 

 by ignorant clerks. 



These failures need alarm no one ; they simply prove what 



