Near the southern extremity of the western coast of Ireland there is a little harbor called Valentia, as you will see by referring to a map.  It faces the Atlantic Ocean, and the nearest point on the opposite shore is a sheltered bay prettily named Heart’s Content, in Newfoundland.  The waters between are the stormiest in the world, wrathy with hurricanes and cyclones, and seldom smooth even in the calm months of midsummer.  The distance across is nearly two thousand miles, and the depth gradually increases to a maximum of three miles.  Between these two points of land—­Valentia in Ireland and Heart’s Content in Newfoundland—­a magical rope is laid, binding America to Europe with a firm bond, and enabling people in London to send instantaneous messages to those in New York.  It is the first successful Atlantic cable, and my piece was cut from it before it was laid.  Fig. 2 on the next page shows how a section of it looks, and Fig. 3 shows a section of the shore ends, which are larger.

Copper is one of the best conductors of electricity known, and hence the wires in the center are made of that metal.  Water, too, is an excellent conductor, and if the wires were not closely protected, the electricity would pass from them into the sea, instead of carrying its message the whole length of the line.  Therefore, the wires must be encased or insulated in some material that will not admit water and is not itself a conductor.  Gutta-percha meets these needs, and the hemp and galvanized wire are added for the strength and protection they afford to the whole.

It was an American who first thought of laying such an electric cable as this under the turbulent Atlantic.  Some foolish people laughed at the idea and declared it to be impracticable.  How could a slender cord, two thousand miles long, be lowered from an unsteady vessel to the bottom of the ocean without break?  It would part under the strain put upon it, and it would be attacked by marine monsters, twisted and broken by the currents.  At one point the bed of the sea suddenly sinks from a depth of two hundred and ten fathoms to a depth of two thousand and fifty fathoms.  Here the strain on the cable as it passed over the ship’s stern would be so great that it certainly must break.  More than this, the slightest flaw—­a hole smaller than a pin’s head—­in the gutta-percha insulator would spoil the entire work, and no remedy would be possible.  A great many people spoke in this way when the Atlantic cable was first thought of, as others, years before, had spoken of Watt and Stephenson.  But Watt invented the steam-engine, Stephenson invented the locomotive, and Cyrus Field bound Great Britain to the United States by telegraph.