22 THE ADDRESSES, LECTURES, ETC., OF 



miralty in the usual way, the ground presented a moderate incline 

 (shown by the dotted lines on the diagram Fig. 4, Plate 1), but 

 which afterwards turned out to be a great chasm. A cable being 

 laid over a chasm like that, has a poor chance of being taken to 

 the bottom, because whatever slack you may give, and there was 

 28 per cent, given in this instance, it all slides down in a straight 

 line, and accumulates at the bottom. Supposing the cable suddenly 

 to touch upon a promontory, it will at once be arrested there and 

 remain suspended in a straight line, because the tenacious mud or 

 ooze which covers the bottom of the ocean, prevents the loose or 

 spare cable on both ends of the suspended piece from sliding 

 towards it to allow of its sinking to the bottom, and the piece of 

 cable thus suspended, under great strain in a catenary curve of 

 perhaps two miles length, must break sooner or later. This cable 

 was, however, partially recovered from a great depth, and hae since 

 been submerged between Marsala and Bona, forming a link in 

 the chain of telegraphs which unite France with its African 

 dependency. 



It may here be reasonably objected that a cable ought never to 

 have been laid upon such ground, and, further, that if the ground 

 could not be avoided, the soundings ought to have revealed the 

 chasm across which the cable fell, in order that special precau- 

 tionary measures might have been adopted to meet the case. The 

 answer is, that a line of soundings which had been taken carefully 

 by the French Admiralty showed no such chasm, but that unfor- 

 tunately the pilot vessel mistook its course during the laying of the 

 cable, and approached Carthagena in a line deviating by about 

 two miles towards Cape Pallos from the line of sounding. The 

 coast about Carthagena, being of a decidedly volcanic formation, 

 might certainly have been avoided altogether, and a much safer 

 landing place might have been found near Cape de Gate ; but 

 although this had been strongly urged, it had been refused to the 

 contractors owing to some previous international arrangement 

 which was not to be disturbed. This accident proves, however, the 

 great necessity for careful and more extensive soundings than those 

 which have hitherto preceded the establishment of deep-sea cables; it 

 also goes to prove, that in passing over very irregular ground, it is 

 not sufficient to allow considerably more cable to run overboard 

 than to cover the distance passed over by the cable-ship. The 



