ADDENDA. 359 



where it is four knots the hour, to be 2000 fathoms in depth, and 

 to reach down to the bed of the ocean with that velocity and press- 

 ure, the scouring action of water under such a weight and mo- 

 tion would fret and wear, break and tear up the very bed and bot- 

 tom of the sea. 



The discovery of facts like these has proved of the greatest val- 

 ue to those concerned in establishing lines of submarine telegraph. 

 The French government, in ignorance of the status of the deep sea, 

 has made two attempts to lay a cable from Sardinia to Al,2:eria. 

 There was failure each time, with great loss, for the cable was one 

 of iron wire, of immense weight, and stout enough to hold the lar- 

 gest ship, but the currents and the storms parted it, or made it 

 necessary for those on board to cut or perish. Its core was of 

 gutta percha, in which were contained the conducting wires. 



The systematic attempt to explore the depths of the sea, and to 

 investigate its winds and currents, which has been inaugurated at 

 the National Observatory, has brought to light the fact that the 

 core alone, without the iivn cable, or any casing save that of the 

 insulating material, is strong enough to resist all forces at the bot- 

 tom of the sea ; that the forces of the currents through which the 

 cable has to sink and while it is sinking are the forces, and the 

 only forces, which try its strength ; and if resistance be offered, no 

 cable, as the French have proved, is strong enough to withstand 

 them and sink. It was a cable of this sort which was lost in the 

 laying between Newfoundland and Cape Breton during the sum- 

 mer of 1855. The currents of the sea are to be overcome, not by 

 resisting, but by yielding. The sea, if obstruction or resistance 

 be offered to its waves, will dash the strongest works of man to 

 pieces, and sport with the wreck like toys, while the tiny nauti- 

 lus, by yielding to them, will defy the most violent ragings of the 

 sea, and ride its billows triumphantly in the utmost fury of the 

 storm. So with the gutta percha core and its conducting wire of 

 copper : if it be paid out slack into the deep sea, so that it will 

 yield to the currents, drifting with them hither and thither while 

 it is sinking through them, it will soon pass beyond their reach, 

 and be lodged on the bottom without any the slightest trial of its 

 strength. 



