354 Mr. Jeffreys on Animal Life at Great Depths in the Sea. 



XXIX. — On a presumed Cause of Failure in Oceanic Telegraphy ; 

 and on the Existence of Animal Life at Great Depths in the Sea. 

 By J. GwYN Jeffreys, Esq., F.R.S., F.G.S. 



To the Editors of the Annals and Magazine of Natural History. 

 Gentlemen, 



Public attention having been of late attracted to the subject 

 of submarine telegraphy, and especially to the causes of failure 

 in several of these undertakings, it may not be uninteresting to 

 mention some facts which have fallen under my observation. 



During the recent expedition to survey the North Atlantic 

 Telegraph line, there was only one piece of drift-wood met with 

 in the Arctic Sea which showed any marks of having been per- 

 forated by marine animals ; and this piece of wood has, through 

 the kindness of Sir Leopold M'Clintock, been submitted to my 

 examination. It had formed part of a fir-tree, and was picked 

 up by the 'Fox' on the 13th Sept. 1860, off the east coast of 

 Greenland, in lat. 60° 54' N., long. 41° 58' W. It appeared to 

 have been much rubbed and frayed, probably by attrition against 

 loose or floating ice. On making sections of this piece of wood, 

 I found that the perforations had been caused by a kind of 

 Annelid, and that they extended to a considerable depth, although 

 they were of a different nature from the tunnels made by any 

 kind of Teredo. Having referred to the account given by the 

 late Sir John Ross of his ' Voyage of Discovery to the Arctic 

 Regions,' which was published in 1819, I find that in many of 

 the deep-sea soundings, which he so accurately recorded, living 

 "sea- worms" (or Annelids) occurred at depths varying from 

 192 to 1000 fathoms. 



The inference I would draw from the fact of animal life exist- 

 ing at great depths in the sea (and which has been lately con- 

 firmed by Dr. Wallich) is, that proper precautions ought to be 

 taken to prevent the cable being injured, and the telegraphic 

 action affected, by marine animals of perforating habits. No 

 vegetable substance is free from their attacks; and I have 

 shown, in the case of the Mediterranean line, that the cable, as 

 well as its enclosure of gutta percha, was pierced, at a depth of 

 between 60 and 70 fathoms, by the Xylophaga dorsalis. I think 

 a sheathing of copper, or of any other metal which is not liable 

 to oxidation, would effectually prevent any such injury, and not 

 interfere with the flexibility of the cable. 



I may take this opportunity of remarking, in justice to the 

 memory of the gallant officer to whose explorations I have above 

 referred, that by means of his " deep-sea clamm '' ha succeeded 

 in taking up and bringing to the surface considerable quantities 



