advantage where the load is not heavy and continuous. The cable has been superseded by electric systems almost entirely.
Ca′bles, Electric, are wires especially prepared for carrying electric currents underground or under water. The underground cable consists essentially of a cylinder of insulating material, such as guttapercha, in which are imbedded one or more copper wires. These coppper wires do not touch each other throughout their length. The guttapercha keeps the moisture out and keeps the electric current in. The cable is generally placed inside a lead sheathing, which preserves its flexibility and at the same time furnishes protection from mechanical injury. It is now the custom to put a large number of conductors—sometimes, for telephone lines, as many as a hundred—in one lead sheath.
Ca′bles, Ocean, telegraph lines laid from shore to shore beneath the sea. The first Atlantic cable was successfully laid in 1866 by Cyrus W. Field. Submarine telegraph lines had already for some years been in operation over short distances. Coney Island and Fire Island had been successfully connected. In Europe a cable had been laid from Dover to Calais, and many others over distances less than a hundred miles. In deeper waters, also, cables had been laid, one from Newfoundland to Cape Breton and another from Spezia to Corsica. In 1857 Mr. Field made his first attempt to lay a cable under the Atlantic from Newfoundland to Valentia in Ireland. This attempt failed, as did several others. In 1858 a cable was laid which worked at first but became silent after a few weeks. In 1865 the Great Eastern took on board a vast cable weighing 20,000 tons, and laid 1,200 miles of it, when by a sudden lurch of the ship the cable was snapped. The next year's attempt was, however, successful. The cable, 2,000 miles long, was safely stretched across the ocean, and submarine communication was an accomplished fact. Its first message was the news that a treaty had been signed by Prussia and Austria.
By 1903 there were 16 cables carrying messages through the Atlantic Ocean, besides three that are no longer used. But the greatest triumph of cable-laying was the completion of the British Pacific cable, 7,800 nautical miles long, which now connects British Columbia with Australia. In 1903 an American cable was laid to the Philippines from San Francisco by way of Hawaii. Thus, by means of the overland telegraph and the submarine cable, it is now possible to transmit a message in a few hours to almost any country on the globe.
Submarine Cables are laid on the bottom of the sea. They require not only good insulation, but great tensile strength, else they will not support their own weights when lowered from the vessel to the bottom of the sea. This tensile strength is acquired by wrapping the guttapercha insulation with a sheathing of steel wire. There now are 16 cables of this type across the Atlantic Ocean, each carrying two copper conductors. Each of these conductors is capable of transmitting about 20 words a minute. See Telegraph.
Cabot (kăb′ŭt), John or Giovanni, probably the discoverer of North America. Very little is known of the life of this seaman. The place and time of his birth and death are not known. Either a Venetian or an Englishman naturalized in 1476, he was living in England in 1495. It probably was the voyage of Columbus in search of the East Indies which started Cabot westward on the same quest. He with his three sons obtained a patent in 1496 from Henry VII, giving them power to search for lands in the eastern, western or northern seas and, as vassals of England, to occupy any lands discovered, with a right to their commerce on paying the king a fifth of all profits. Accompanied by his three sons he set sail in 1497, and on June 24th sighted Cape Breton Island and Nova Scotia. He planted on the coast the banners of England and Venice and returned. The next year another patent was granted, but nothing further is known of his life.
Cab′ot, Sebastian, son of John Cabot, was probably born between 1474 and 1477, either at Bristol or at Venice. He accompanied his father on his voyage to Nova Scotia, and in 1498 he sailed with two ships in search of a northwestern passage to India. He left a few men on the bleak shores of Newfoundland and sailed southward along the American coast as far as Florida. Later he entered the service of Spain, and in 1526 commanded an expedition which examined the coast of Brazil and the River Plata, and there attempted to plant colonies. In 1547 he again went to England and became inspector of the navy. He was the prime mover of the expedition of merchant adventurers which opened to England an important trade with Russia. He was famous as the maker of maps, and he was probably the first who made sure that America was wholly a new and unknown continent. He died at London in 1557.
Cabul. See Kabul.
Cac′tus. The general name of a well-known family called the Cactaceæ. The numerous species are characteristic of the warm and dry regions of America, their display being greatest in Mexico. There are about 1,000 recognized species, and many of them are under cultivation on account of their curious forms. They have become remarkably adapted to con-
