Eclectic Magazine of Foreign Literature, Science, and Art, May 1885

by Various

In connection with the subject of telegraphy, and as an instance of the versatility of Dr. Siemens’s inventive powers, I may point out that in 1876 he brought out the pneumatic postal telegraph tube, by which, as is pretty generally known, written messages are blown or sucked through tubes on various metropolitan routes, instead of being transmitted electrically. About the same time, also, he constructed his ingenious bathometer, for ascertaining the depth of the sea at any given point, without the tedious operation of sounding; and some years previously he worked out his electrical thermometer or pyrometer, enabling the observer to read the temperature (whenever he desired) at any distant and inaccessible point, such as the top of a mountain, the bottom of the sea, the air between the layers of a cable, or the interior of a furnace.

Probably the most prominent idea associated in the public mind with the name of Siemens is that of electric lighting, and perhaps electric tram and railroads. As I have more than once pointed out in this room, the dynamo-machine, by which mechanical energy is converted into that form of energy known as electricity (which may be used both for lighting and for the transmission of power), is derived from a principle discovered by Faraday in 1831. Sir William Siemens’ devotion to this, and the important practical consequences which he deduced from it, constitute another example of that mental characteristic to which I have already alluded. Faraday’s discovery, briefly described, was that when a bar magnet was suddenly inserted into a coil of wire, or when a wire was suddenly moved through a magnetic field, a momentary current of electricity was developed in the wire. Although this current is exceedingly small and brief, it is capable of unlimited multiplication by mechanical arrangements of a simple kind. One means for accomplishing this multiplication was the Siemens armature of 1857, which consisted, at first, of a piece of iron with wire wound round it longitudinally, not transversely, the whole to be rotated between the poles of a powerful magnet; in its present form it is one of the most powerful and perfect things of its kind, and the evolution of the Siemens armature, as we now have it, from the rudimentary type of a quarter of a century ago, has been characterised by Sir W. Thomson as one of the most beautiful products of inventive genius, and more like the growth of a flower than to almost anything else in the way of mechanism made by man.

Ten years afterwards came his classical paper “On the Conversion of Dynamical into Electrical Force, without the use of permanent Magnetism,” which was read before the Royal Society on February 14, 1867. Strangely enough, the discovery of the same principle was enunciated at the same meeting by Sir Charles Wheatstone, while there is yet a third claimant in the person of Mr. Cromwell Varley, who had previously applied for a patent in which the idea was embodied. It can never be quite certain, therefore, who was the first discoverer of the principle upon which modern dynamo-machines are constructed. I need not describe here the way in which this principle is carried out in all dynamo-machines. Suffice it to say that they differ from Faraday’s magneto-electric machines in having electro-magnets in the place of permanent steel magnets, and that these electro-magnets are, if I may be allowed the expression, self-excited by the play of mutual give and take between the armature and the magnet.

It was the invention of the dynamo-machine which made practicable the application of electricity to industrial purposes. Experiments have shown that it is capable of transforming into electrical work 90 per cent. of the mechanical energy employed as motive power. Its practical application is still in its infancy. In 1785 Watt completed his “improvements” in the steam-engine, and the century which has since elapsed has not sufficed to demonstrate the full extent of its utility. What may we not expect in the next hundred years from the extension of the dynamo-machine to practical purposes?

In the development of appliances for the production of the electric light Sir William Siemens took a leading part, and, as is well known, his firm has been facile princeps at all the important electrical exhibitions. But while ever zealous to promote its progress, he never took a partisan view of its utility, candidly admitting that gas must continue to be the poor man’s friend. In 1882 he told the Society of Arts that “Electricity must win the day as the light of luxury, but gas will find an ever-increasing application for the more humble purposes of diffusing light.”

In the hands of Dr. Siemens the enormous energy displayed in the Electric Arc was applied to other purposes than mere lighting. In June, 1880, he greatly astonished the Society of Telegraph Engineers by exhibiting the power of an electrical furnace designed by him to melt considerable quantities of such exceedingly refractory metals as platinum, iridium, &c. He explained that he was led to undertake experiments with this end in view by the consideration that a good steam-engine converts 15 per cent. of the energy of coal into mechanical effect, while a good dynamo-machine is capable of converting 80 per cent. of the mechanical into electrical energy. If the latter could be expended without loss in an electric furnace, it would doubtless far exceed in economy any known air furnace.

Moreover Sir William Siemens may fairly be described as the creator of electro-horticulture. Some experiments which he made early in 1880 led him to the conclusion that the electric light could influence the production of coloring matter in leaves, and promote the ripening of fruit at all seasons of the year, and at all hours of the day and night. In the following winter he put these conclusions to the test of experience on a large scale at his country house, Sherwood, near Tunbridge Wells, and the results obtained were communicated to the British Association at York in 1881, in a paper, the value of which was recognised by its receiving the rare distinction of being printed in full in the annual report.

Some photographs, which he kindly allowed me to take, represent the difference between three kinds of corn grown under ordinary conditions, and the same corn, under the same conditions, with the added stimulus of the electric light from sunset to sunrise. He came to the conclusion that, although periodic darkness evidently favors growth in the sense of elongating the stalks of plants, the continuous stimulus of light was favorable to a healthy development at a greatly accelerated pace, through all the stages of the annual life of the plant, from the early leaf to the ripened fruit.

I have left until the last any notice of a field of work which the Messrs. Siemens may be truly said to have made peculiarly their own, viz., the electrical transmission and distribution of power; for I firmly believe that in the future, although not perhaps in the near future, the practical consequences of this will be such as are little dreamed of now; and this opinion is, I know, held by men far more competent to judge than I am.

In March, 1877, Dr. Siemens startled the world, in his address to the Iron and Steel Institute, by his proposal to transmit to distant points some of the energy of the Falls of Niagara. As I have before explained in this room, the electrical transmission of energy depends upon the fact that a dynamo-machine may be used either to convert mechanical into electrical energy, or to effect the reverse change. Hence to transmit power in this way, two dynamo-machines, connected by a metallic conducting rod, or cable, are necessary; the first, at the water-fall or other source of power, produces the electrical energy, which, in its turn, is reconverted into mechanical power by the second dynamo at the other end of the line. In his own grounds at Tunbridge Wells he made numerous experiments in this subject, distributing the power from a central steam-engine over various parts of his farm, there to perform different functions. The most interesting practical examples, as yet, are to be seen in the electric railroads erected and worked by Siemens Brothers in Paris, Berlin, Vienna, &c., and in the Electric Tramroad at Portrush. The special interest of this line lies in the fact that it was the first real application to railroads of “waste energy,” inasmuch as the cars are propelled by the power of a water-fall eight miles off! The last occasion on which I had the privilege of meeting Sir William Siemens was when, honored by his invitation, I was present at the opening of this line in September 28, 1883. On that occasion, which, half-a-century hence, will be as memorable as the opening of the Stockton and Darlington railroad, the Lord Lieutenant of Ireland recognised the fact that this was an entirely new departure in the development of the resources of Ireland, and Sir William Siemens, in a most characteristic speech, admitted that, had he known the difficulties before him, he should have thought twice before he said “Yes” to Dr. Traill’s question as to whether the proposed line could be worked electrically, but that, having said “Yes,” he was determined to carry out the project. As illustrating the character of the man, I may here quote the saying common in his workshops, that as soon as any particular problem had been given up by everybody as a bad job, it had only to be taken to Dr. Siemens for him to suggest half-a-dozen ways of solving it, two of which would be complicated and impracticable, two difficult, and two perfectly satisfactory.