SUBMARINE CABLES. 



Ireland. He found that between Newfoundland, or the mouth cf 

 the river St. Lawrence, and the west coast of Ireland, the bottom 

 consists of a plateau, which, as he says, " seems to have been placed 

 there especially for the purpose of holding the wires of a submarine 

 telegraph, and of keeping them out of harm's way. It is neither 

 too deep nor too shallow ; yet it is so deep, that the wires but once 

 landed, will remain for ever beyond the reach of vessels, anchors, 

 icebergs, and drifts of any kind ; and so shallow that the wires 

 may be readily lodged upon the bottom. 



" The depth of this plateau is quite regular, gradually increasing 

 from the shores of Newfoundland to the depth of 1500 to 2000 

 fathoms, as you approach the other side."* 



Lieutenant Maury concludes that this line of deep sea soundings 

 is quite decisive of the question, as to the practicability of a 

 submarine telegraph between the two continents in so far as the 

 bottom of the ocean is concerned. A cable laid across would pass 

 to the north of the great banks, and would be deposited upon the 

 plateau above described, where the waters of the ocean are proved 

 to be " as still as those of a millpond." 



This inference Lieutenant Maury deduces from the fact, that 

 all the specimens of the bottom brought up have been found to 

 consist of miscroscopic shells without the admixture of a single 

 particle of gravel or sand. Had there been currents at those 

 depths, these shells would have been thrown about and abraded, 

 and mixed more or less with the debris of the natural bed of the 

 ocean, such as ooze, sand, gravel, and other matter. "Con- 

 sequently a telegraphic cable once laid there, there it would 

 remain as completely beyond the reach of accident as if it were 

 buried in air-tight cases." 



Imperfectly informed persons have expressed an opinion that 

 the cable would not sink below a certain depth, at which the 

 increasing density of the sea water would render it bulk for bulk 

 as heavy as the cable. The well known physical properties of 

 water prove such a supposition to be groundless. Although not 

 incompressible in an absolute sense, water is susceptible of com- 

 pression, even at the greatest depths of the ocean, in so small a 

 degree, that the cable must always greatly exceed it in specific- 

 weight. 



Putting out of view the financial part of the question, there 

 appears then to be no good reason for pronouncing the project to 

 construct such a cable, and to deposit it in the bed of the ocean, 

 impracticable in an absolute, sense. 



* Report of Lieutenant Maury to the Secretary of the U. S. Navy, 

 Feb. 22, 



