27 APRIL 1867, Page 19

EARLY PRESENTIMENTS OF THE ELECTRIC TELEGRAPH.* ONE of the most

extraordinary facts in the whole history of the Sciences and Arts, is the strong presentiment which existed for a eentury or more at the revival of learning that magnetism would be used to convey intelligence without regard to time or space. Just as there is now a kind of presentiment that electricity will supersede steam, or just as it was long thought that a philoso- pher's stone would one day be discovered to turn all things to gold, or an elixir of life to banish old age, so the magic girdle which connects land and land beneath the waves of the ocean was not unknown to the scientific dreamers of the Baconian age.

Fifty wild things indeed are anticipated for the one thing which turns out true. The squaring of the circle, the petpetuum sympathetic cures, and the whole budget of paradoxes have * Railways, Steamers, and Telegraphs : a Glance at their Recent Progress and Pre- sent State. By George Dodd, author of the Food of London, &c. W. and R. Chambers, London and Edinburgh. 1867.

agitated the brains and excited the hopes of unfortunate genius for centuries back, but now these things are acknowledged to be illusory and impossible. And yet that which might have seemed most illusory and impossible is an accomplished fact.

In his very interesting account of the gradual triumph of the electric telegraph, Mr. Dodd has referred to this strange presenti- ment, and has given a quotation of the passnge in the Prolusiones of Strada, published in 1617, which describes in the most exact manner the working of the Telegraph in 1867. Let a person who has used the latest form of Mr. Wheatstone's household letter telegraph try to describe the procedure, and we think he could not describe it better than in the following words :— "If you wish your distant friend, to whom no letter can come, to learn something, take a disk Lor dial], and write round the edge of it the letters of the alphabet., in the order in which children learn them, and in the centre place horizontally a rod, which has touched a magnet, so that it may move and indicate whatever letter you wish."

A similar dial being in the possession of your friend,— " If you desire privately to speak to the friend whom some share of the earth holds far from you, lay your hand on the globe, and turn the movable iron as you see disposed along the margin of all the letters which arc required for the words. Hither and thither, turn the style and touch the letters' now this one, and now that Vonderful to relate, the far distant friend sees the voluble iron tremble without the touch of any person, and run now hither, now thither ; conscious, he bends over it, and marks the teaching of the rod. When he sees the rod stand still, he in his turn, if he thinks there is anything. to be answered, in like manner, by touching the various letters, writes it back to his friend."

No wonder that Strada, as he finishes this description, should break forth into the prayer :—

" 0 utinam haec ratio scribendi prodeat usu! Gautier at citior propararet epistola, nullas Latronum veHta insidias, fluviosque morantos."

"0 would that this method of writing might be brought into use ! More safely and swiftly would the letter be speeded, fearing neither the snares of robbers, nor the delaying rivers."

Mr. Dodd suggests that in this wonderful description Strada was merely giving play to his imagination. In the midst of Strada's classical triftes, it was doubtless a mere play of the im- agination. When Addison, in the Spectator (No. 241), alludes to Strada's description, he speaks of it as "an account of a chi- merical correspondence between two friends by the help of a certain loadstone :"— " If Monsieur Scudery," he continues, "or any other writer of romance, had introduced a necromancer, who is generally in the train of a knight-errant, making a present to two lovers of a couple of these above-mentioned needles, the reader would not have been a little pleased to have seen them corresponding with one another when they were guarded by spies and watches, or separated by castles and adventures. In the meanwhile, if ever this invention should be revived or put in practice, I would propose that upon the lovers' dial-plate there should be written not only the four-and-twenty letters, but several entire words, which have always a place in passionate epistles."

But though in the hands of poets and literary men this notion of a space-destroying telegraph was a fanciful chimera, among the scientific men of the day it was gravely discussed or mysteriously hinted at. From about the middle of the sixteenth to the end of the seventeenth century it is alluded to in most works on magne- tism, and many other books of science. The Marquis of Worcester was a diligent collector of all the ingenious notions of his age, and he probably alludes to magnetism when he speaks of "Intel- ligence at a distance communicative, and not limited to distance, nor by it the time prolonged" (Dirch's Life of Worcester, p. 357).

Sir Thomas Browne, in his Pseudodoxia Epidemica, says of a supposed magnetic telegraph that "the conceit is excellent, and if the effect would follow, somewhat divine." He speaks of it as a conceit "whispered thorow the world with some attention, credu- lous and vulgar auditors readily believing it, and more judicious and distinctive heads not altogether rejecting it." But it would appear that, like a true fellow-countryman of Bacon, old Sir Thomas submitted the thing to experiment, and though the needles were at the distance of but half a span, when one was moved "the other would stand like Hercules' pillars." He also raises several objections to this supposed telegraph, such as that the needles would move contrary ways, and that the difference of longitude would prevent two persons from watching their telegraph needles exactly at the same moment.

Joseph Glanvill, in his Scepsis Scientifwa (1665), devotes a chapter to considering three instances of reputed impossibilities. One of these is the magnetic telegraph, which he describes as composed of sympathetic needles and an abecedarian circle. He mentions and controverts the objections of Sir Thomas Browne, suggesting that "there are some hints in natural operations that give us probability that it is feasible." And it is with a strange feeling of wonder that we find a writer 200 years ago concluding in these words, "Though this pretty contrivance possibly may

not yet answer the expectation of inquisitive experiment, yet

no despicable item, that by some other such way of magnetick efficiency, it may hereafter with success be attempted, when magical history shall be enlarged by riper inspections ; and 'Cs not unlikely but that present discoveries might be improved to the performance." The predictions of men are not often so cautiously stated or so completely fulfilled, that we can afford to overlook a sentence such as the above.

Gilbert, the contemporary of Bacon and the founder of the science of Magnetism, does not allude to this imaginary telegraph, so far as we can find, or if he does, he dismisses it among other fancies as unworthy of his great treatise De Magnete. Much about the same time (1629) Nitholaus Cabeus, the Jesuit of Ferrara, wrote his Philosophica Magnetica "It is a fable," he says, " that two men can converse with each other between the most remote and separated places, by the aid of two revolving needles," and he considers that those ought to be severely castigated who with such portentous fables deter men from the study of true causes. Such an effect, he says, cannot be produced by magnets, and he proves the fancy to be an error, "lest any one should be deluded by a vain hope." Vague and erroneous though the notions of a telegraph then were, they were truer than the refutation of Cabeus, grounded on the false principle that "every physical agent determines for itself a certain sphere of activity, beyond which it cannot have any influence."

But the interesting question remains, to whom is due the first suggestion that intelligence may be conveyed by magnetism or electricity ? Strada attributed it to the celebrated Cardinal Bembo, the secretary of Leo X. But Bembo, who died in 1547, was a historian and literary character, and would hardly be likely to form so new a conception of a purely scientific kind.

The earliest work in which we have been able to trace the de- scription of the supposed telegraph is the celebrate& Natural Magic of the Neapolitan Baptista Porta, published in the year 1589. This work is a collection of all that was most wonderful in the sciences then aroused from a long sleep in Italy. His seventh book is on the "Wonders of the Magnet." In the preface he enumerates these wonders, such as the mariner's compass, the perpetual motion, and the sympathetic needles. "I do not fear," he says, "that with a long absent friend, even though he be con- fined by prison walls, we can communicate what we wish by means of two compass needles circumscribed with an alphabet." A few lines before we find him mentioning with great respect Marco Polo, the source of some of his information. But in the eighteenth chapter of the same book we get more probably to the origin of the notions in question. The fact that if a magnet be placed beneath a table it will affect a magnetic needle above the table, in spite of the intervening matter, is mentioned by Porta with much wonder. This is the experiment which seems to have suggested the power of two magnetic needles to act upon each other at a distance, even though prison walls intervened. And strange to say, this experiment may be traced back to the great St. Augustine. " Novit hoc experbnentum Divus Augustinus," says Porta, and an exact description will accordingly be found in Augustine's treatise De Civitate Dei, a work believed to have been begun A.D. 413.

It is the fashion in these days to fall into raptures of wonder and exultation over the magnetic telegraph, but it is not we who have first wondered. Pliny counted the load,stone as the most wonderful thing in nature. "Quid enim mirabilius 7" he asks. "Iron is the strongest thing in nature, and yet before the magnet it becomes docile," he reflects : " cedit, et pa titer mores." All ages, then, have shared in the intelligent wonder excited by the powers of magnetism. It is only the riper inspections of this age that have carried out to the letter the anticipations of former ages. The telegraph of the present time tends to assume exclusively the form most nearly analogous to the coneeptions of Porta. The earliest attempts at an electric telegraph, as Mr. Dodd well relates, were made with frictional electricity, which is not applicable to the purpose. Then galvanism was studied, and the conducting powers of metallic wires becitme understood. Now, the most improved telegraphs consist essentially of a magnet moved in front of one end of a wire, and a magnetic needle which is thereby made to move in front of the other end of the wire. And though a wire is quite indispensable to conduct magnetic influence in one direction, it is a fact that the return current passes back without a wire through land and sea, stayed neither by wall nor mountain, as Porta imagined to himself.

The time is rapidly approaching when Arid's girdle will be completed, and signals will be transmitted round the world in a moment It is idle, perhaps, to suggest that Shakespeare may have had some thought of magnetic communication when he con- ceived that fantastical idea. Certain it is, however, that the conceit of a space-destroying telegraph was "whispered thorow the world with some attention" in his age, and we have thought this to be a fact worthy of being a little better known.