wires wound round spirally like the strands of a rope (fig. 10), the whole forming a cable which is coiled up in the hold of a vessel, and let out as the vessel crosses from one side to the other; in this way the cable is deposited on the bed of the sea or channel, forming an electrical connection from country to country. These cables are made in one piece by machinery. That from Dover to Calais is twenty-five miles long, contains four copper conducting wires, and weighs about 175 tons; that from Dover to Ostend contains six conducting wires, is seventy miles long, weighs nearly 500 tons, and cost about £30,000; its structure (the real size) is shown at fig. 10. Illustration: ELECTRIC TIME BALL, CHARING CROSS. The electric cable now constructed to be laid down between Ireland and America, is composed of seven small copper wires twisted into one, and surrounded by gutta percha; this is then surrounded by eighteen small wire-ropes, each composed of seven small wires twisted together, the whole being in its section not larger than a four-penny-piece; 2000 miles of this cable are now ready to be laid down. A plan was some time ago put in practice by which the correct time could be kept at various places by electric communication with the time at Greenwich; a clock thus regulated, is situated at Charing Cross, and a ball placed at the top of the electric telegraph station there, is caused by the same means to fall exactly at one o’clock. A contrivance has of late been patented to work the electric telegraph by steam, and the following account of it is extracted from the “Times:”--