possibility of an electric wire crossing Ireland, and forming a part of one continuous wire uniting these capitals, along which streams of intelligence, political, commercial, and social, would be constantly flowing?

It is curious to observe how often that which is regarded as fantastical and chimerical in one age, acquires the character of cold reality in another. Strada, in one of his prolusions, says Addison,

"Gives an account of a chimerical correspondence between two friends by the help of a certain loadstone, which had such a virtue in it, that if touched by two several needles, when one of these needles so touched began to move, the other, though at ever so great a distance, moved at the same time and in the same manner. He tells us that two friends, being each of them possessed of these needles, made a kind of dial-plate, inscribing it with twenty-four letters, in the same manner as the hours of the day are marked upon the ordinary dial-plate. They then fixed one of the needles on each of these plates in such a manner, that it could move round without impediment, so as to point to any of the twenty-four letters. Upon their separating from one another into distant countries, they agreed to withdraw themselves punctually into their closets at a certain hour of the day, and to converse with one another by this their invention. Accordingly, when they were some hundred miles asunder, each of them shut himself up in his closet at the time appointed, and immediately cast his eye upon the dial-plate. If he had a mind to write anything to his friend, he directed his needle to every letter

that formed the words that he had occasion for, making a little pause at the end of every word or sentence, to avoid confusion. The friend, in the meanwhile, saw his own sympathetic needle moving of itself to every letter which that of his correspondent pointed at. By this means, they talked together across a whole continent, and conveyed their thoughts to one another in an instant over cities or mountains, seas or deserts.

"If M. Scudery, or any other writer of romance (continues Addison) had introduced a necromancer, who is generally in the train of a knight-errant, making a present to two

lovers of a couple of those abovementioned 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 on the lover's dial-plate there should be written, not only the twenty-four letters but several entire words, which have always a place in passionate epistles ;_as flames, darts, die, language, absence, Cupid, heart, eyes, hang, drown, and the like. This would very much abridge the lover's pains in this way of writing a letter, as it would enable him to express the most useful and significant words with a single turn of the needle."

Addison wrote this in 1711. Had he lived an hundred and forty years later he would have seen not only the sympathetic needles of Strada, but even the alphabetic dial literally realised. The form of magnetic telegraph invented by M. Siemens, and constructed and in operation on some of the Prussian lines, presents the precise form described by Strada. The needles established at two distant stations play upon two dials, on which, instead of the twelve hours, are engraved the twenty-four letters, and the electric current and the mechanism connected with it cause the needles to move sympathetically. Whatever letter one is made to point at, the other instantly turns to the same, though they should be separated by "cities or mountains, seas or deserts."

even

But he might witness still greater miracles. A lover in London might write an epistle to his mistress in Vienna, the handle of the pen being in London, and its point and the sheet of paper on which the letter is written, being in Vienna! By a further improvement, which is announced in one of the memoirs recently read before the French Institute, it appears that an individual can, by means of

the electro-chemical telegraph, produce written characters in ordinary writing upon paper placed at any distance from the writer. Thus, a merchant at London may take a pen in his hand, and with it write a letter or draw a bill; this letter, or this bill, shall at the same moment be committed to paper, letter for letter, and word for word, in any desired place telegraphically connected with London, in Petersburgh for example, and such letter or bill, so written, shall be in the handwriting, and shall be signed with the usual signature of the writer, and this shall be accomplished instantly upon the movement of the pen in the hands of the writer in London !

The method of working this last miracle is not given in detail, but it is indicated with sufficient clearness to enable an adept to comprehend its principle.

At the moment we are engaged upon this article, a circumstance has occurred so closely connected with the application of physical discoveries to elevated purposes, that we cannot forbear to advert to it.

Of all the wonderful discoveries which modern science has given birth to, there is perhaps not one which has been applied to useful purposes on a scale so unexpectedly contracted as that by which we are enabled to penetrate into the immense ocean of air with which our globe is surrounded, and to examine the physical phenomena which are manifested in its upper strata. One would have supposed that the moment the power was conferred upon us to leave the surface of the earth, and rise above the clouds into the superior regions, a thousand eager inquirers would present themselves as agents in researches in a region so completely untrodden, if such term may here be permitted.

Nevertheless, this great invention of ærial navigation has remained almost barren. If we except the celebrated ærial voyage of Gay-Lussac in 1804, the balloon, with its wonderful powers, has been allowed to degenerate into a mere theatrical exhibition, exciting the vacant and unreflecting wonder of the multitude. Instead of being an instrument of philosophical research, it has become a mere expedient for profit in the hands of charlatans, so

much so, that, on the occasion to which we are now about to advert, the persons who engaged in the project incurred failure, and risked their lives, from their aversion to avail themselves of the experience of those who had made ærostation a mere spectacle for profit. They thought that to touch pitch they must be defiled, and preferred danger and the risk of failure to such association.

It is now about two months since M. Barral, a chemist of some distinction at Paris, and M. Bixio, a member of the Legislative Assembly (whose name will be remembered in connexion with the bloody insurrection of June, 1848, when, bravely and humanely discharging his duty in attempting to turn his guilty fellow-citizens from their course, he nearly shared the fate of the Archbishop, and was severely wounded), resolved upon making a grand experi ment with a view to observe and record the meteorological phenomena of the strata of the atmosphere, at a greater height and with more precision than had hitherto been accomplished. from the motives which we have explained, the project was kept secret, and it was resolved that the experiment should be made at an hour of the morning, and under circumstances, which would prevent it from degenerating into an exhibition. MM. Arago and Regnault undertook to supply the ærial voyagers with a programme of the proposed performance, and instruments suited to the projected observations. M. Arago prepared the programme, in which was stated clearly what observations were to be made at every stage of the ascensional movement.

But

It was intended that the balloon should be so managed as to come to rest at certain altitudes, when barometric, thermometric, hygrometric, polariscopic, and other observations, were to be taken and noted; the balloon after each series of observations to make a new ascent.

The precious instruments by which these observations were to be made were prepared, and in some cases actually fabricated and graduated, by the hands of M. Regnault himself.

To provide the balloon and its appendages, recourse was had to some of those persons who have followed the fabrication of balloons as a sort of trade, for the purposes of exhibition.

In this part of their enterprise the

voyagers were not so fortunate, as we shall presently see, and still less so in having taken the resolution to ascend alone, unaccompanied by a practised æronaut. It is probable that if they had selected a person, such as Mr. Green, for example, who had already made frequent ascents for the mere purpose of exhibition, and who had become familiar with the practical management of the machine, a much more favourable result would have ensued. As it was, the two voyagers ascended for the first time, and placed themselves in a position like that of a natural philosopher, who, without previous practice, should undertake to drive a locomotive, with its train, on a railway at fifty miles an hour, rejecting the humble but indispensable aid of an experienced engine-driver.

The necessary preparations having been made, and the programme and the instruments prepared, it was resolved to make the ascent from the garden behind the Observatory at Paris, a plateau of some elevation, and free from buildings and other obstacles, at day-break of Saturday, the 29th June. At midnight the balloon was brought to the spot, but the inflation was not completed until nearly 10 o'clock, A.M.

It has since been proved that the balloon was old and worn, and that it ought not to have been supplied for such an occasion.

It was obviously patched, and it is now known that two sempstresses were employed during the preceding day in mending it, and some stitching even was found necessary after it had arrived at the Observatory.

The net-work which included and supported the car was new, and not originally made with a view to the balloon it enclosed, the consequences of which will be presently seen.

The night, between Friday and Saturday, was one of continual rain, and the balloon and its netting became thoroughly saturated with moisture. By the time the inflation had been completed, it became evident that the network was too small; but in the anxiety to carry into effect the project, the consequences of this were most unaccountably overlooked. We say unaccountably, because it is extremely dif ficult to conceive how experimental philosophers and practised observers, like MM. Arago and Regnault, to say nothing of numerous subordinate

scientific agents who were present, did not anticipate what must have ensued in the upper regions of the air. Nevertheless, such was the fact.

On the morning of Saturday, the instruments being duly deposited in the car, the two enterprising voyagers placed themselves in it, and the balloon, which previously had been held down by the strength of twenty men, was liberated, and left to plunge into the ocean of air, at twenty-seven minutes after ten o'clock.

The weather, as we have already stated, was unfavourable the sky being charged with clouds. As it was the purpose of this project to examine much higher regions of the atmosphere than those which it had been customary for æronautic exhibitors to rise to, the arrangements of ballast and inflation which were adopted were such as to cause the ascent to be infinitely more rapid than in the case of public exhibitions; in short, the balloon darted upwards with the speed of an arrow, and in two minutes from the moment it was liberated, that is to say, at twenty-nine minutes past ten, plunged into the clouds, and was withdrawn from the anxious view of the distinguished persons assembled in the garden of the Observatory.

While passing through this dense cloud, the voyagers carefully observed the barometer, and knew by the rapid fall of the mercury that they were ascending with a great velocity. Fifteen minutes elapsed before they emerged from the cloud; when they did so, however, a glorious spectacle presented itself. The balloon, emerging from the superior surface of the cloud, rose under a splendid canopy of azure, and shone with the rays of a brilliant sun. The cloud which they had just passed was soon seen several thousand feet below them. From the observations taken with the barometer and thermometer, it was afterwards found that the thickness of the cloud through which they had passed was 9,800 feet-a little less than two miles. On emerging from the cloud, our observers examined the barometer, and found that the mercury had fallen to the height of 18 inches; the thermometer showed a temperature of 45° Fahr. The height of the balloon above the level of the sea was then 14,200 feet. At the moment of emerging from the cloud, M. Barral made polariscopic observa

tion, which established a fact foreseen by M. Arago, that the light reflected from the surface of the clouds was unpolarised light.

The continued and somewhat consilerable fall of the barometer informed the observers that their ascent still continued to be rapid. The rain which had previously fallen, and which wetted the balloon, and saturated the cordage forming the net-work, had now ceased, or, to speak more correctly, the balloon had passed above the region in which the rain prevailed. The strong action of the sun, and almost complete dryness of the air in which the vast machine now floated, caused the evaporation of the moisture which enveloped it. The cordage and the balloon becoming dry, and thus relieved of a certain weight of liquid, was affected as though a quantity of ballast had been thrown out, and it darted upwards with increased velocity.

It was within one minute of eleven when the observers, finding the barometer cease the upward motion, and finding that the machine oscillated round a position of equilibrium by noticing the bearing of the sun, they found the epoch favourable for another series of observations. The barometer there indicated that the balloon had attained the enormous height of 19,700 feet. The moisture which had invested the thermometer had frozen upon it, and obstructed, for the moment, observations with it. It was while M. Barral was occupied in wiping the icicles from it, that, turning his eye upwards, he beheld what would have been sufficient to have made the stoutest heart quail with fear.

To explain the catastrophe which at this moment, and at nearly 20,000 feet above the surface of the earth, and about a mile above the highest strata of the clouds, menaced the voyagers, we must recur to what we have already stated in reference to the balloon and the net-work. As it was intended to ascend to an unusual altitude, it was of course known that in consequence of the highly rarefied state of the atmosphere, and its very much diminished pressure, the gas contained in the balloon would have a great tendency to distend, and consequently space must be allowed for the play of this effect. The balloon, therefore, at starting, was not nearly filled with gas, and yet, as we have explained it, very

nearly filled the net-work which enclosed it. Is it not strange that some among the scientific men present did not foresee, that when it would ascend into a highly rarefied atmosphere, it would necessarily distend itself to such a magnitude, that the netting would be utterly insufficient to contain it? Such effect, so strangely unforeseen, now disclosed itself practically realised to the astonished and terrified eyes of M. Barral.

The balloon, in fact, had so swelled as not only completely to fill the netting which covered it, but to force its way, in a frightful manner, through the hoop under it, from which the car and the voyagers were suspended.

In short, the inflated silk protruding downwards through the hoop, now nearly touched the heads of the voyagers. In this emergency the remedy was sufficiently obvious.

The valve must be opened, and the balloon breathed, so as to relieve it from the over-inflation. Now it is well known that the valve in this machine is placed in a sort of sleeve, of a length more or less considerable, connected with the lower part of the balloon, through which sleeve the string of the valve passes. M. Barral, on looking for this sleeve, found that it had disappeared. Further search showed that the balloon being awkwardly and improperly placed in the enclosing network, the valve-sleeve, instead of hanging clear of the hoop, had been gathered up in the net-work above the hoop; so that, to reach it, it would have been necessary to have forced a passage between the inflated silk and the hoop.

Now here it must be observed, that such an incident could never have happened to the most commonly-practised balloon exhibitor, whose first measure, before leaving the ground, would be to secure access to, and the play of the valve. This, however, was, in the present case, fatally overlooked. It was, in fine, now quite apparent that either of two effects must speedily ensue-viz., either the car and the voyagers would be buried in the inflated silk which was descending upon them, and thus they would be suffocated; or that the force of distention must burst the balloon. If a rupture were to take place in that part immediately over the car, then the voyagers would be suffocated by an atmosphere of hydrogen; if it should take place at a superior part, then the

balloon, rapidly discharged of its gas, would be precipitated to the earth, and the destruction of its occupants rendered inevitable.

Under these circumstances the voyagers did not lose their presence of mind, but calmly considered their situation, and promptly decided upon the course to be adopted. M. Barral climbed up the side of the car, and the net-work suspending it, and forced his way through the hoop, so as to catch hold of the valve-sleeve. In this operation, however, he was obliged to exercise a force which produced a rent in a part of the silk below the hoop, and immediately over the car. In a moment the hydrogen gas issued with terrible force from the balloon, and the voyagers found themselves involved in an atmosphere of it.

Respiration became impossible, and they were nearly suffocated. A glance at the barometer, however, showed them that they were falling to the ground with the most fearful rapidity.

During a few moments they experienced all the anguish attending asphyxia. From this situation, however, they were relieved more speedily than they could then have imagined possible; but the cause which relieved them soon became evident, and inspired them with fresh terrors.

M. Barral, from the indications of the barometer, knew that they were being precipitated to the surface of the earth with a velocity so prodigious, that the passage of the balloon through the atmosphere dispelled the mass of hydrogen with which they had been surrounded.

It was, nevertheless, evident that the small rent which had been produced in the lower part of the balloon, by the abortive attempt to obtain access to the valve, could not have been the cause of a fall so rapid.

M. Barral accordingly proceeded to examine the external surface of the balloon, as far as it was visible from the car, and, to his astonishment and terror, he discovered that a rupture had taken place, and that a rent was made about five feet in length along the equator of the machine, through which, of course, the gas was now escaping in immense quantities. Here was the cause of the frightful precipitation of the descent, and a source of imminent danger in the fall.

M. Barral promptly decided on the course to be taken.

It was resolved to check the descent by the discharge of the ballast, and every other article of weight. But this process, to be effectual, required to be conducted with considerable coolness and skill. They were some thousand feet above the clouds. If the ballast were dismissed too soon, the balloon must again acquire a perilous velocity before it would reach the earth. If, on the other hand, its descent were not moderated in time, its fall might become so precipitate as to be ungovernable. Nine or ten sand-bags being, therefore, reserved for the last and critical moment, all the rest of the ballast was discharged. The fall being still frightfully rapid, the voyagers cast out, as they descended through the cloud already mentioned, every article of weight which they had, among which were the blankets and woollen clothing which they had brought to cover them in the upper regions of the atmosphere, their shoes, several bottles of wine, all, in fine, save and except the philosophical instruments. These they regarded as the soldier does his flag, not to be surrendered save with life. M. Bixio, when about to throw over a trifling apparatus, called an aspirator, composed of copper, and filled with water, was forbidden by M. Barral, and obeyed the injunction.

They soon emerged from the lower stratum of the cloud, through which they had fallen in less than two minutes, having taken fifteen minutes to ascend through it. The earth was now in sight, and they were dropping upon it like a stone. Every weighty article had been dismissed, except the nine sand-bags which had been designedly reserved to break the shock on arriving at the surface. They observed that they were directly over some vinegrounds near Lagny, in the department of the Seine and Marne, and could distinctly see a number of labourers engaged in their ordinary toil, who regarded with unmeasured astonishment the enormous object about to drop upon them. It was only when they arrived at a few hundred feet from the surface that the nine bags of sand were dropped by M. Barral, and by this manœuvre the lives of the voyagers were probably saved. The bal. loon reached the ground, and the car struck among the vines. Happily the wind was gentle; but gentle as it was it was sufficient, acting upon the enor