MAKING AND LAYING SUBMARINE CABLES 175 
It is very common about the Irish coasts, where it has seriously 
damaged several cables. 
To mitigate the attacks of these marine creatures, the con • 
ducting wire of recently made cables has been covered by an 
Upper Part. Lower Part. 
Fig. 114. 
inner sheathing that excludes the larger animals, and this plan 
appears well deserving of a trial. 
Sharks, Saw-fish , and Whales .—Sharks have attacked cables 
in Florida and left the marks of their bites. The same thing 
Fig. 115. 
has happened with one of the cables on the coast of China, and 
with one of the exposed parts of the cable between Malta and 
Alexandria. In the last case, one of the shark’s teeth remained 
fixed in the gutta-percha. 
1 
