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surface, must exert a distinct influence upon the earth's magnetic condition.

Of Faraday's purely theoretical speculations, especially on force and matter, it is very difficult to form a just conception ; they are so singular, and so different from the ideas which men of science now usually hold on these subjects; they are expressed in language often beautiful, but concerning the exact meaning of which it is frequently most difficult to get a clear notion. His mind appears from early times to have been pervaded by two fixed ideas : in the first place, by the conviction that all the manifestations of energy are somehow connected; and in the second, that the action of forces at a distance without a chain of influence binding them together, is an absurdity. All his chief speculations ran in one or other of these two channels. He was constantly experimentalising upon the interaction of the forces of nature:' seeking in this way he discovered Voltaic induction, magneto-electricity, the action of magnetism on light, and the universality of the magnetic condition of matter. He was constantly engaged in trying to bring gravitation itself into the charmed circle, but never succeeded, and wrote a paper describing his negative experiments entitled • Notes on the possible Relation of Gravity

with Electricity or Heat,' but this was not published. Then he, like Boscovich, thought that all the phenomena of nature could be accounted for without the supposition of the existence of matter, by assuming certain centres of force. The effects observed are thus supposed to be brought about by the interaction of various forces exerting themselves at a given point in space, and not, as is generally believed, by the different affections of matter. His idea of Force' was that of a concrete existence totally at variance with the definition of the mathematician, viz., that which produces or tends to produce

motion. It certainly at first sight appears to be a singular fact that although Faraday's mind seemed to be constantly working in this direction, and although he possessed experimental power of the very highest kind, yet he did not attempt to make quantitative determinations of the equivalence of these various forms of energy; thus, for instance, of expressing heat in terms of mechanical motion. This want (as it certainly appears) in Faraday's mind arose from the fact that he did not fully comprehend the limits of the laws of energy as understood by mathematicians, whilst the difficulty (in the end a metaphysical one) which he felt in believing that two bodies at a distance could act upon one another, led him to assume the existence of lines of force' binding as it were the

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bodies together. These lines of force he actually sees in the curves which iron filings range themselves round a magnet, and his vivid imagination pictures to his mind's eye the existence of similar lines of force' whenever any action at a distance occurs; thus he speaks of the illumination of the magnetic lines of force,' he recognises various kinds of lines

of force, lines of gravitating force, those of electro-static induc' tion, those of magnetic action, and others partaking of a dynamic character might be perhaps included.'

'Force,' says Tyndall, seemed to him an entity dwelling along the line in which it is exerted. The lines along which gravity acts between the sun and the earth seem figured in his mind as so many elastic strings : indeed he accepts the assumed instantaneity of gravity as the expression of the enormous elasticity of the “lines of weight." When he goes into the open air and permits the helices to fall, to his mind's eye they are tearing through the lines of gravitating power, and hence his hope and conviction that an effect would and ought to be produced. . :. So long did he brood upon these lines, so habitually did he associate them with his experiments on induced currents, that he could not think much without them. “I have been so accustomed to " employ them, and especially in my last researches, that I have un“ wittingly become prejudiced in their favour, and ceased to be a clear“ sighted judge. Nevertheless I have always endeavoured to make “ experiment the test and controller of theory and opinion.” “The

study of these lines,” he says again, “has at different times been “greatly influential in leading me to various results which, I think, “prove their utility as well as fertility."

We ought therefore perhaps not to be surprised that Faraday, holding views of this kind, did not attempt the experimental investigation of the mechanical equivalent of heat or of electricity, or that these things, perhaps the greatest of all the achievements of modern science, were left for other men to accomplish. At the same time we must acknowledge that Faraday's genius appears to have seen the possibility of certain generalisations in these most recondite subjects, which although they do not flow from the laws of energy, yet have a certain connexion with the views of the most advanced school of mathematical physicists, viz. the ultimate dynamical condition of matter.

Even in the last chapter of Faraday's life, each one of his grent qualities can be very distinctly traced. Few of those who saw him enjoying the kindness which gave him his house in Hampton Court, or delighting in the beauty of the sunsets from the Palace Gardens, or rejoicing in the idleness of the summer life in the country, knew that during a great part of this period of his life he was proving by experiments whether his magneto-electric light could be made by Professor Holmes practically useful for lighthouses.

'His

energy and truthfulness made him take the whole responsibility of the decision upon himself; and without doubt, his frequent journeys to the South Foreland and Dungeness lighthouses, and his night excursions in the Channel during the winter, when he was seventy years old, were remote causes of his last illness.

• Throughout all the reports which he made regarding the light, there is scarcely a word to show that he ever thought of it as his light, his greatest discovery; he even heard others call it their light without making a remark; but he gave all credit and honour to him who applied it, and only said of himself, that he must take care " that we “ do not lead our authorities into error by the advice given.”

• Another remarkable instance of his humility may be seen at the end of the chapter in his burial. He knew full well that he had earned his monument in the consecrated palace of the dead, but he “ desired a “ gravestone of the most ordinary kind in the simplest earthly place;" the unconsecrated ground he thought good enough to be his grave, and the silent service at his funeral consisted only of the tears and thoughts of the few relations whom he wished to have there.'

We cannot more aptly close this slight sketch of a great man's character and works than by transcribing the following extract from M. Dumas' eloquent and heart-stirring Eloge:

"Je ne sais s'il existe au monde un savant qui ne fût heureux de laisser en mourant des travaux pareils à ceux dont Faraday a fait jouir ses contemporains et qu'il a légués à la postérité; mais je suis sur que tous ceux qui l'ont connu voudraient approcher de cette perfection morale qu'il atteignait sans effort. Elle semblait chez lui comme une grâce naturelle, qui en faisait un professeur plein de feu pour la diffusion de la vérité, un artiste infatigable, plein d'entrain et de gaieté dans son laboratoire, le meilleur et le plus doux des hommes au sein de sa famille, et le prédicateur le mieux inspiré au milieu de l'humble troupeau religieux dont il suivait la foi.

* La simplicité de son cæur, sa candeur, son amour ardent de la vérité, sa franche sympathie pour tous les succès, son admiration naïve pour les découvertes d'autrui, sa modestie naturelle, dès qu'il s'agissait des siennes, son âme noble, indépendante et fière, tout cet ensemble donnait un charme incomparable à la physionomie de l'illustre physicien.

« Nous nous étions rencontrés dans notre jeunesse, à une époque où l'un et l'autre nous en étions à nos débuts. Nous nous sommes retrouvés souvent, lorsque ses brillantes découvertes excitaient la curiosité universelle, et pourtant, dans le laboratoire intime, quand il reproduisait pour moi la suite de ses expériences fondamentales, je me surprenais à oublier la science pour observer le savant, distrait des merveilles qu'il dévoilait dans la nature physique, par le désir de surprendre le secret de cette perfection morale qui se manifestait dans tous les mouvements de son âme.'

Art. VIII.-1. Special Report from the Select Conmittee on

the Electric Telegraph Bill ; together with Minutes of Evi

dence, London : 1868. 2. Electric Telegraphs Returns to an Order of the Honourable

the House of Commons, April, 1868. London. 3. The Ocean Telegraph to India; a Narrative and a Diary.

By J. C. PARKINSON. London : 1870. IN N tracing out the beginning of any great scientific discovery,

it is instructive to consider upon what apparently inconsiderable elements it is built up. Just as the raised beach which withstands the most dangerous seas and makes new geographical outlines is constructed of loose stones, thrown together by various agencies, totally ignorant of what will be the result of their labours, so many of our most important inventions have been prepared unconsciously by different minds, until some comprehensive genius links them together for a great purpose.

No discovery of modern times better illustrates this observation than that of the electric telegraph. The bare fact that a flash of electricity would traverse a wire of considerable length was discovered by Grey and Wheeler as far back as 1729 ; and this may be considered the first step in the discovery; but it was wholly sterile, in the absence of any means by which the current could be made to speak. Nearly a century elapsed before Oersted, in 1819, invented this tongue in the shape of the magnetic needle, which, upon being placed on a pivot parallel to a coil of wire charged with an electric current, assumed a position at right angles to it; this tongue was only capable of making one motion or sign, but this was sufficient to set other minds upon the track. . Arago in the same year discovered that the electric fluid possessed the power of imparting magnetism to soft iron, and our own countryman Sturgeon, by simply coiling fine copper wire insulated with silk round a piece of this metal, invented the electro-magnet. Hence, by the mere fact of making or breaking contact, the iron became magnetised or demagnetised; or, in other words, motion was produced at the end of a distant wire, by means of an armature, which was either attracted by the magnet, or which recoiled by the aid of a spring, when the electric current was drawn from it at the will of the operator. Here, for some inexplicable reason however, the progress of the discovery for a time stopped; the clue was in

VOL. CXXXII. NO. CCLXIX.

* P

the hands of the philosophers, but the circumstances were wanting to lead them on. The attempt of Ronalds to interest the Government of the day in an electric telegraph he had invented, was nipped in the bud by cold officialism, which, in answer to a proposal from him, made the usual red tape answer, that the telegraph was of no use in times of peace, and

that the semaphore in time of war answered all the required ' purpose. Although Ronalds' telegraph never could have had much practical success, his scheme no doubt set others thinking, and we rejoice that he has lived to receive in his old age the honour of knighthood as a reward for his ingenuity.

But although no sign was made, many minds were simultaneously at work at the great problem. Professor Wheatstone was measuring the velocity of the electric current, and announced the astounding fact, as early as 1834, that a current could be passed eleven times round the earth, or 288,000 miles, in one second. The announcement of a fact outstripping the most visionary ideas of the poet, making Puck by comparison the merest laggard, was the flower speedily to be followed by more astonishing fruit.

In the year 1837, almost simultaneously, three telegraphs were invented; Professor Wheatstone, having consulted with Mr. Cooke, who had been working in the same groove, patented with him a telegraph having five wires and five needles working upon the face of a lozenge-shaped dial, on which the letters of the alphabet were inscribed. This patent was dated in June, and by the end of July, having obtained permission to lay down the wires on the North-Western Railway, between Euston Square and Camden Town station, on the 25th of that month it was put in operation. At the risk of repeating an old story, we cannot help relating the first public utterances of the new tongue destined to be spoken throughout the globe.* The audience who listened were all representatives of the new ideas revolutionising the world. Mr. Stephenson and Mr. Charles Fox were the first to hear this new form of human language--electric speech. On the evening of the 25th of the month, in a dingy wooden outhouse close to the booking-office at Euston Square, illuminated by a dip candle, Professor Wheatstone with his friends, with beating hearts, as the inventor

• We may refer our readers to an article on Ocean Telegraphy,' published in this Journal in January 1861, for some account of the earlier stages of the invention. But the immense progress made since that time now calls for a more extended notice.

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