第37章

This admirable cable steamer of 5,000 tons register was built for Messrs. Siemens Brothers by Messrs. Mitchell & Co., at Newcastle. The designs were mainly inspired by Siemens himself; and after the Hooper, now the Silvertown, she was the second ship expressly built for cable purposes. All the latest improvements that electric science and naval engineering could suggest were in her united. With a length of 360feet, a width of 52 feet, and a depth of 36 feet in the hold, she was fitted with a rudder at each end, either of which could be locked when desired, and the other brought into play. Two screw propellers, actuated by a pair of compound engines, were the means of driving the vessel, and they were placed at a slight angle to each other, so that when the engines were worked in opposite directions the Faraday could turn completely round in her own length. Moreover, as the ship could steam forwards or backwards with equal ease, it became unnecessary to pass the cable forward before hauling it in, if a fault were discovered in the part submerged: the motion of the ship had only to be reversed, the stern rudder fixed, and the bow rudder turned, while a small engine was employed to haul the cable back over the stern drum, which had been used a few minutes before to pay it out.

The first expedition of the Faraday was the laying of the Direct United States cable in the winter of 1874 a work which, though interrupted by stormy weather, was resumed and completed in the summer of 1875. She has been engaged in laying several Atlantic cables since, and has been fitted with the electric light, a resource which has proved of the utmost service, not only in facilitating the night operations of paying-out, but in guarding the ship from collision with icebergs in foggy weather off the North American coast.

Mention of the electric light brings us to an important act of the inventor, which, though done on behalf of his brother Werner, was pregnant with great consequences. This was his announcement before a meeting of the Royal Society, held on February 14, 1867, of the discovery of the principle of reinforcing the field magnetism of magneto-electric generators by part or the whole of the current generated in the revolving armature--a principle which has been applied in the dynamo-electric machines, now so much used for producing electric light and effecting the transmission of power to a distance by means of the electric current. By a curious coincidence the same principle was enunciated by Sir Charles Wheatstone at the very same meeting; while a few months previously Mr. S. A. Varley had lodged an application for a British patent, in which the same idea was set forth. The claims of these three inventors to priority in the discovery were, however, anticipated by at least one other investigator, Herr Soren Hjorth, believed to be a Dane by birth, and still remembered by a few living electricians, though forgotten by the scientific world at large, until his neglected specification was unexpectedly dug out of the musty archives of the British Patent Office and brought into the light.

The announcement of Siemens and Wheatstone came at an apter time than Hjorth's, and was more conspicuously made. Above all, in the affluent and enterprising hands of the brothers Siemens, it was not suffered to lie sterile, and the Siemens dynamo-electric machine was its offspring.

This dynamo, as is well known, differs from those of Gramme and Paccinotti chiefly in the longitudinal winding of the armature, and it is unnecessary to describe it here. It has been adapted by its inventors to all kinds of electrical work, electrotyping, telegraphy, electric lighting, and the propulsion of vehicles.

The first electric tramway run at Berlin in 1879 was followed by another at Dusseldorf in 1880, and a third at Paris in 1881. With all of these the name of Werner Siemens was chiefly associated; but William Siemens had also taken up the matter, and established at his country house of Sherwood, near Tunbridge Wells, an arrangement of dynamos and water-wheel, by which the power of a neighbouring stream was made to light the house, cut chaff turn washing-machines, and perform other household duties. More recently the construction of the electric railway from Portrush to Bushmills, at the Giant's Causeway, engaged his attention; and this, the first work of its kind in the United Kingdom, and to all appearance the pioneer of many similar lines, was one of his very last undertakings.

In the recent development of electric lighting, William Siemens, whose fame had been steadily growing, was a recognised leader, although he himself made no great discoveries therein. As a public man and a manufacturer of great resources his influence in assisting the introduction of the light has been immense. The number of Siemens machines and Siemens electric lamps, together with measuring instruments such as the Siemens electro-dynamometer, which has been supplied to different parts of the world by the firm of which he was the head, is very considerable, and probably exceeds that of any other manufacturer, at least in this country.

Employing a staff of skilful assistants to develop many of his ideas, Dr. Siemens was able to produce a great variety of electrical instruments for measuring and other auxiliary purposes, all of which bear the name of his firm, and have proved exceedingly useful in a practical sense.