ERIAL.

ÆROGRAPHY.

Definition.

Principle.

ERIAL ACID, in Chemistry, carbonic acid. See CHEMISTRY, Div. ii.

ERIAL PERSPECTIVE, that branch of the science of Perspective which regards the relative diminution of the colours of bodies in proportion to their distance from the eye. See COLOUR and PAINTING, Div. ii. ÆRIFORM FLUIDS, in Chemistry, a name sometimes given to the different gasses. See CHEMISTRY, Div. ii. EROGRAPHY (ano, air, and ypaow I write), the

A term ERO

science of describing the air and its properties. A term in little use; but formerly embracing what is now GRAPHY treated under Air, Aerology, Meteorology, &c. EROLITHS (ano, air, and Aboç, a stone), a name NAUTICS AEROsometimes given to those mineral substances which occasionally fall through the atmosphere. Some have considered them as concretions actually formed in the air, but no satisfactory theory respecting them has yet been given.

AERONAUTICS, from anp, the air, and vavrin, the art of navigation; signifies the art of navigating through the air, and is therefore adopted as a more appropriate term for our present subject than that usually employed, Aerostation, which properly denotes the weighing of air, or the weighing of bodies suspended in the air.

In sketching the history and progress of this art, we shall not detain the reader with recounting the fabulous stories of ancient excursions through the atmosphere, but proceed at once to the first propagation of the art of aerial navigation in Europe towards the conclusion of the last century.

From principles long known, and which will be found established in our treatise of Hydrostatics, it follows, that any body which is specifically lighter than a fluid, will float in it; and consequently a mass bulk for bulk lighter than the atmosphere, or the air encompassing the earth, will be buoyed up by it, and will ascend for the same reason that a cork, or a blown bladder would rise in water, supposing either of these to be in the first instance immersed at any given depth below its surface. If the atmosphere were every where of the same density as at the terrestrial surface, and a mass could be obtained specifically lighter, such a mass would not only rise in the first moments, but it would continue to ascend to the upper surface of this medium; and having attained that situation, it would there remain in a quiescent state, or float along upon the surface, having neither the power to ascend, nor any tendency to descend, except that which is resisted by the upper pressure of the fluid. But as the air is compressible and elastic, its density continually decreases as we ascend, and therefore a body can only rise in such a medium to an elevation at which the air is of the same density as itself.

This principle, as we have observed above,has been long known, and various projects have in consequence been formed for producing a mass of sufficient rarity to effect the purpose of aerial ascensions; but most of these schemes were merely imaginary, and are entitled to little notice: we shall therefore only mention two of them, which seem to approach the nearest in idea to the present Proposition practice of aeronautics. The jesuit Francis Lana, contemporary with bishop Wilkins, proposed to exhaust hollow balls of metal of their internal air, and by that means to render them specifically lighter than the atmosphere, and determine them to ascend, as represented in Plate 1. This idea, in a theoretical point of view, is unexceptionable, but the means were certainly insufficient for the practical performance of the experiment; for vessels of copper of any manageable dimensions, made sufficiently thin to float in the atmosphere, would be

of Lana.

of Gusman

utterly unable to resist the external pressure to which Experimen they must necessarily be exposed. The second case we have to mention seems entitled to more consideration; being represented as an actual experiment, made in the beginning of the last century by Gusman, a Portuguese friar, who is reported to have launched a paper bag into the air, which ascended to the height of 200 feet. We have no particulars of this experiment, but if the recorded account of the ascent of the bag be correct, it must have been something very similar to the first air balloons.

Dr. Black, of Edinburgh, soon after Cavendish's Dr. Black's discovery of the specific gravity of inflammable air, suggestion. suggested that if a bladder sufficiently light and thin were filled with this air, it would form a mass lighter than the same bulk of atmospheric air, and rise in it. This thought was suggested in his lectures in 1767 and 1768; and he proposed, by means of the allentois of a calf, to try the experiment: this, however, he was prevented by his other employments from carrying into effect. The possibility of constructing a vessel, which, when filled with inflammable air, wouldascend in the atmosphere, had occurred also to Mr. Cavallo about the same time; and to him belongs the Cavallo's honour of having first made experiments on this sub- experiject in the beginning of the year 1782, of which an ments. account was read to the Royal Society on the 20th of June in that year. He first tried bladders, but the thinnest of these, however, scraped and cleaned, were too heavy. In using China paper, he found that the inflammable air passed through its pores like water through a sieve; and having failed of success in blowing this air into thick solutions of gum, varnishes, and oil paint, he was under the necessity of being satisfied with soap balls, which, being inflated with inflammable air, by dipping the end of a small glass tube, connected with a bladder containing the air, into a thick solution of soap, and then gently compressing the bladder, ascended rapidly in the atmosphere; and these are doubtless the first inflammable air balloons that ever were made.

The practice and science of aeronautics is not, how- Montgol ever, to be considered as springing from the above fier's expe experiments, for while these were yet unfinished, and riment. even perhaps before the soap balls had been made to ascend, Stephen and John Montgolfier, natives of An nonay, in France, and masters of a considerable manufactory there, had turned their attention to the subject, and in the same year- their first experiment was made at Avignon; by applying to an apertufe in a fine silk bag some lighted paper, which rarified the air, and caused it to ascend to the perpendicular height of 70 feet. After this, various experiments were tried upon

AERO a large scale, which greatly excited the public curiosity. NAUTICS. An immense bag of linen, lined with paper, and containing upwards of 23,000 cubic feet, was found to have a power of lifting about 500 lbs. including its own weight. Burning chopped straw and wool under the aperture of this machine, it immediately occasioned it to swell, and afterwards to ascend into the atmosphere with such rapidity, that in ten minutes it had risen to a height of 6000 feet, when its force being exhausted, it fell to the ground at the distance of 7668 feet from the place whence it departed.

Animals

Not long after this, one of the brothers, invited by the Academy of Sciences at Paris to repeat his experiment at their expence, constructed a large balloon of an elliptical form. In a preliminary experiment, this balloon lifted from the ground eight persons who held it, and would have ascended with them, had not others came quickly to their assistance.

On the following day the machine was filled by the ascend in a combustion of fifty pounds of straw, and twelve pounds of wool, with which it soon became inflated, and sustained itself in the air, together with a weight of between four hundred and five hundred pounds. A few days after this, a new balloon was constructed, 60 feet in height, and 48 feet in diameter; and with this, in a wicker cage, were sent a sheep, a cock, and a duck. The entire success of this experiment, however, was prevented by a sudden gust of wind, which tore the machine in two places near the top before it as cended; still, however, it was estimated to have risen 1440 feet; and after remaining in the air about eight minutes, it fell to the ground, about two miles from the place whence it departed, and without the animals having received the slightest injury.

Rozier.

These experiments and others, which it would be useless to enumerate, having shown that such aërostatic machines were capable of carrying up great weights, and consequently men, with great safety, Pilatre de M. Pilatre de Rozier offered himself to be the first aerial adventurer, with a new machine, constructed in the fauxbourg of St. Antoine. This was of an elliptical or oval form, 48 feet in diameter, and 74 feet in height, and was elegantly painted and ornamented. A proper gallery and grate enabled the aeronaut to supply the fire with fuel, and thus to keep up the machine as long as he pleased; the weight of which, with the apparatus, &c. was about 1600 lbs. On the 15th of October, 1783, M. Pilatre, placing himself in the gallery, inflated the balloon, and permitted it to ascend to the height of 84 feet, where he kept it afloat about four or five minutes; after which it descended very gently: but such was still its tendency to ascend, that it rebounded to a considerable height after touching the ground. He then repeated the experiment, and ascended to the height of 210 feet; he afterwards rose 262 feet, and in the descent this third time, a gust of wind having blown the machine over some trees in an adjoining garden, M. Pilatre, by throwing a little fuel on the fire, rose again sufficiently to extricate himself from this difficulty; and thus demonstated the practicability of the management of such machines.

ther as

1. Pilatre.

Soon after this, the same adventurous philosopher s of again ascended with M. Girond de Villette, to the height of 330 feet, hovering over Paris at least nine minutes, in sight of thousands of spectators; the machine preserving, during all this time, a steady position.

On the 21st of November, 1783, M. Pilatre again AEROascended with the marquis d'Arlandes. Their voyage NAUTICS. occupied about 25 minutes, the aeronauts having, in that time, passed over a space of about five miles. In this ascent it appears there was some danger of the machine taking fire, the marquis having observed several holes made by the fire in the lower parts; the application, however, of a wet sponge was found to be sufficient to stop the progress of combustion, and they descended in safety.

This last voyage may be said to conclude the history of aerostatic machines elevated by means of heated air: for they were found in some degree inconvenient, on account of the impossibility of keeping up the elevated temperature of the enclosed air, without the continued renewal of fuel, and that in considerable quantity; whereby the aëronauts were exposed to great danger, from the occasional sudden and unavoidable expansion of the flame, and their inability to command that uniformity of rarefaction so necessary to the safety of the

voyage.

As aërial chemistry had been before this time making rapid advances, so the philosophical world, through the indefatigable labours of Cavendish, had been made acquainted with the properties of inflammable air, whose specific gravity, in a tolerably pure state, is at least twelve times lighter than atmospheric air. We have noticed the suggestion to which this discovery had given rise in the lectures of Dr. Black, and the experiments of Cavallo, by which the truth of these suggestions was in part demonstrated. It was very natural, therefore, after the success that had attended the experiments on heated air balloons, that the attention of philosophers should be drawn towards the completion of their purpose by the application of this inflammable air, or, as we now term it, hydrogen gas.

cend with an hydrogen

gas balloon.

The first machine of this kind was launched on the Charles and continent by M. M. Roberts and Charles, in 1783, and Roberts assuch was the great convenience of these machines compared with those elevated by heated air, that they soon became almost exclusively adopted; yet even these possessed some disadvantages, particularly that of the aeronaut not being able to raise or lower them without a loss of ballast in the first instance, and of gas in the latter; the filling of them was also attended with considerable expense. These defects suggested the idea of enclosing a bag of common air, in one of inflammable air, whereby, in varying the temperature of this inner balloon, the whole apparatus could be raised or lowered ad libitum.

Chatres.

The first attempt conformably to this idea, was made Ascent of by the duke de Chatres. He placed a small balloon the duke de within the greater one, the former being filled with common air by means of a pair of bellows, when necessary, viz. whenever it was thought proper to descend, it being supposed, that the machine would thus become heavier, and the air in the outer balloon condensed, and consequently, that the ascent or descent might be effected at pleasure. The circumstances, however, of this voyage were so unfavorable, that it could not be ascertained whether or not the experiment would have succeeded, in a more serene state of the atmosphere, the weather being so boisterous during the whole time, that the duke had a very narrow escape with his life.

The above scheme for raising or lowering an aeros

AERO tatic machine by bags filled with common air, being NAUTICS. thus rendered dubious, another method was suggested, which was to put a small aërostatic machine with rarefied air under an inflammable air balloon, but at such a distance that the inflammable air in the latter, might be perfectly out of the reach of the fire employed for inflating the former; and thus, by increasing or diminishing the fire applied to the small machine, the absolute gravity of the whole mass might be considerably reduced or augmented.

Fatal ascent of Pilatre and Romaine.

Guyton Morveau and Bertrand.

This scheme was unfortunately put in execution by the celebrated Pilatre and M. Romaine. Their inflammable air balloon was about thirty seven feet in diameter, and the power of that of rarefied air was about sixty pounds. They ascended without any accident; but had not been long in the atmosphere when the upper balloon was seen to swell very considerably, at the same time the aeronauts were observed, by means of telescopes, very anxious to descend, being busily pulling the valve and opening the appendages to the balloon in order to facilitate the escape of as much inflammable air as possible. Shortly after this, the machine took fire, at the height of nearly a mile from the ground. No explosion was heard, and the silk balloon seemed at first to oppose some resistance to the descent for about a minute, after which, however, it collapsed, and descended with the two unfortunate travellers with such rapidity, that both of them were killed. Pilatre seems to have been dead before he came to the ground, but M. Romaine was still alive when some persons came up to him; he expired, however, immediately after. This fatal experiment, which cost the life of the first and most intrepid aëronaut, was undertaken on the 15th of June, 1785, the ascent having taken place at Boulogne, with the intention of crossing the English channel to repay the visit which Dr. Jeffries and M. Blanchard made to the French coast, on the 7th of January of the same year.

We have introduced this account of the unfortunate Pilatre de Rozier, in consequence of the similarity of his experiment to that of the duke de Chatres; but prior to this, certain other ascents were made that appear to be deserving of some detail, especially that of the celebrated chemist Guyton Morveau, who ascended from Dijon in a balloon, nearly of a globular shape, 29 feet in diameter, composed of the finest varnished silk, and filled with hydrogen gas. He was accompanied by the Abbé Bertrand, and took his departure about five o'clock in the evening; the barometer being then 29-3 inches, and the thermometer at 57° Fahrenheit's scale. After surmounting some accidents, they rose to an altitude of nearly two English miles, where the barometer had sunk to 19.8 inches, and the thermometer to 25°. They felt no inconvenience, however, except from the pinching of their ears from cold. They saw an ocean of clouds below them, and in this situation witnessed, as the day declined, the beautiful phenomenon of a parhelion, or mock-sun. At this time the real luminary was only ten degrees above the horizon, when all in an instant another sun appeared to plant itself within about six degrees of the former: it consisted of numerous prismatic rings, delicately tinted on a ground of dazzling whiteness. After a voyage of Guyton an hour and a-half they alighted safely at about 15 Morveau's miles distance from the place of their ascent.

second

ascent.

M. Guyton Morveau ascended a second time on the

12th of June, accompanied by the president de Verly. AEROThe machine was launched at seven o'clock in the NAUTICS morning, the mercury in the barometer standing at 294 inches, Fahrenheit's thermometer at 66°, and Saussure's hygrometer at 833. The balloon swelled very fast, in consequence of the increasing heat of the sun, and the upper valve being at intervals opened to give vent to the excess of gas, the latter escaped with a noise resembling the rushing of water. As the aeronauts did not rise to a very great elevation, they enjoyed an agreeable temperature, and could easily, by observing the situation of the different villages scattered below them, trace out their route with tolerable accuracy on the surface of the map. By nine o'clock they had reached the height of 6030 feet, as appeared from the barometer, which now stood at 24-7 inches, the thermometer at 70°, and the hygrometer at 654. They descended three quarters of an hour afterwards, about 12 miles from Dijon.

The

But the most remarkable voyage which had yet been Testn's performed, was that of M. Testu, who ascended from ascent Paris on the 18th of June, 1786, with a balloon 29 feet in diameter, of glazed tiffany, furnished with auxiliary wings, and filled as usual with hydrogen gas. ascent took place at about four o'clock in the afternoon, the barometer standing at 29-68 inches, and the thermometer so high as 84°, though the day was cloudy, with an apparent prospect of rain. The balloon had only been about five-sixths filled, but it gradually swelled as it became drier and warmer, and acquired its full distention at the height of 2800 feet; when, in order to avoid the waste of gas, or the rupture of the machine, the voyager endeavoured to lower the balloon by the re-action of his wings; but they were found insufficient for this purpose: he did, however, at length descend in a corn-field, in the plain of Montmorency, where he had the mortification to be taken prisoner by the farmer and several peasants, who insisted upon his paying the damages that the curiosity of his followers had occasioned. Anxious to get clear of such troublesome attendants, he persuaded them, that since his wings were broken, he and his balloon were at their mercy, and they drew both along, in supposed triumph, for some distance, by cords fixed to the car; till M. Testu finding that the loss of his wings, cloak, &c. had rendered the apparatus much lighter, suddenly cut the cord, and took an abrupt leave of the farmer and his men.

He now rose to the region of the clouds, where he saw small frozen particles floating in the atmosphere, and heard thunder rolling beneath his feet. As the coolness of the evening advanced, the buoyant force of his machine diminished, and he again approached the ground, a little before seven o'clock, near the abbey of Royaumont. Here he threw out some ballast, and in the space of twelve minutes, rose to the height of 2,400 feet, where the thermometer stood at 66°. He now heard the blast of a horn, and could perceive huntsmen below in full chase. Curious to witness the sport, he opened the valve, and descended between Etouen and Varville, when rejecting his oars, he began to collect some ballast, and while he was thus employed, the huntsmen gallopped up to him. He then mounted a third time, and passed through a dense body of clouds, in which thunder followed flashes of lightning in quick succession. The thermometer fell

AERO- to 21°, but afterwards, when the balloon had reached MUTICS. the height of 3,000 feet, regained its former point of 56°. In this region the aëronaut remained till nearly nine o'clock, and at this time witnessed the setting of the sun; immediately after which, he was involved in thick masses of thunder clouds: lightnings flashed on all sides, succeeded by loud claps of thunder, while snow and sleet fell copiously around him. The thermometer, was then sunk to 21°, as he perceived by the help of a phosphoric light which he had struck for that purpose.

amardi's

In this tremendous situation the intrepid adventurer remained three hours, the time during which the storm lasted. The balloon was affected by a sort of undulating motion, upwards and downwards, occasioned, as he imagined, by the electric action of the clouds. The lightning appeared excessively vivid; the thunder was sharp and loud, and preceded by a sort of crackling noise. A calm at length succeeded, when he had the pleasure of seeing the stars, and embraced the opportunity of taking some necessary refreshment. At half past two in the morning, day began to appear, and he resolved to descend, which he accomplished about a quarter before four, having already witnessed the setting and rising of the sun. He found himself near the village of Campremi, about sixty-three miles from Paris, perfectly safe, after a voyage which had lasted near twelve hours, under circumstances at one time the most pleasant, and at others, the most terrific it is possible to imagine.

The first aërial voyage in England was performed on ent in the 15th of September, 1784, by Vincent Lunardi, a and native of Italy. His balloon was made of oiled silk, painted in alternate stripes of blue and red, and in diameter, it measured thirty-three feet. From a net which went over about two thirds of it, descended fortyfive cords to a hoop, hanging below; and to this the car or gallery was attached. There was no valve; its neck, which was terminated in the form of a pear, being the aperture through which the hydrogen gas was introduced, was also that through which it might be emitted. Mr. Lunardi departed from the Artillery Ground, at two o'clock, taking with him a dog, a cat, and a pigeon. After throwing out a little ballast to clear the houses, he ascended to a considerable height; about half an hour after three, he descended very near the ground, and landed the cat, which was nearly dead with cold; and then rising, he prosecuted his voyage; but at ten minutes past four he again descended near Ware in Hertfordshire, after a pleasant voyage of two hours.

chard

The second aerial voyage in England, was undertaken Sheidon by M. Blanchard, and Mr. Sheldon, professor of anatomy to the Royal Academy. They ascended at Chelsea, on the 16th of October of the same year, about 12 o'clock. Mr. Sheldon was landed after a short voyage, about fourteen miles from the place of departure; but M. Blanchard then re-ascended, and finally descended near Rumsey in Hampshire, about seventy-five miles distant from London. In this second experiment, M. Blanchard ascended so high, that he found great difficulty in breathing, the air at this height being so rare, that a pigeon sent off from the car, found great difficulty in supporting itself, and at length came and settled on the side of the boat, seeming afraid to attempt the boundless vast by which it was surrounded.

About this time Mr. Sadler made his first aërial AEROexcursion from Oxford; since which date he has NAUTICS. performed several other voyages to the upper regions. One of these was attended with peculiar circum- Sadler. stances, as will be seen in the subsequent part of this article.

Perhaps the most daring attempt that had yet been Blanchard made, was that of M. Blanchard and Dr. Jeffries and Jeffries. across the straits of Dover. This took place on the 7th of January, 1785, being a clear frosty morning, with the wind barely perceptible at N. N.W. The operation of filling the balloon began at 10 o'clock, and a little before one o'clock every thing was ready for their departure. At one o'clock M. Blanchard ordered the boat to be pushed off, which then stood only two feet distant from that precipice, so finely described by Shakespeare in his tragedy of King Lear. As the balloon was scarcely sufficient to carry two men, they were obliged to throw out all their ballast, except three bags of sand, of ten pounds each; when they rose gently, but made little way, on account of the wind being very slight. At a quarter past one the barometer, which on the cliff stood at 297, was fallen to 27.3, and the weather proved fine and warm for the season. They had now a most beautiful prospect of the south coast of England, and were able to count twenty-seven villages upon it. After passing over several vessels, they found that the balloon, at fifty minutes after one, was descending, and they immediately threw out a sack and a half of their ballast; but this being found insufficient, their descent being still more rapid than before, they threw out all that remained: but even this was found to be ineffectual; they therefore next cast out a parcel of books: this caused the balloon to ascend, at a time when they were about midway between France and England; viz. about twelve miles from either shore. At a quarter past two, finding themselves again descending, they threw away the remainder of their books, and about ten minutes after, had a most enchanting prospect of the coast of France. Still, however, as the machine descended, and as they had now no more ballast, they cast out their provisions, the wings of the boat, and every other moveable. "We threw out," says Dr. Jeffries, only bottle, which in its descent cast out a steam like smoke, accompanied with a rushing noise; and when it struck the water, we heard and felt the shock very perceptibly on the car of the balloon." All this proving insufficient to stop the descent of the balloon, they next threw out their anchors and cords, and at last stript off their clothes, and fastening themselves to certain slings, intended to cut away the boat as their last resource. They had, however, now the satisfaction to find that they were rising; and as they passed over the high lands between Cape Blanc and Paris, the machine rose very fast, and carried them to a greater elevation than they had been at any former part of their voyage. They soon after descended safely amongst some trees in the forest of Guiennes, where there was just sufficient opening to admit them. In consequence of this voyage, the king of France presented M. Blanchard with a gift of 12,000 livres, and granted him a pension of 1200 livres a year.

our

We have thus traced the history and practice of this science, from the time of its first introduction to the period above stated, viz. 1786; but it would be useless

Garnerin

a parchute.

AERO to attempt a mere enumeration of the various voyages NAUTICS. that have been since undertaken; we shall therefore select only such as have been made with particular scientific views, or which have been performed under circumstances that render them of particular interest. Blanchard was the first who constructed parachutes, descends in and attached them to balloons, for the purpose of securing himself from the fatal consequences of a rapid fall, in case any accident happened to his machine. In one of his excursions from Lisle, about the end of August, 1785, when he traversed a distance of more than 300 miles without halting, he let down from a great height a dog, by means of a basket fastened to a parachute, and the animal reached the ground unhurt. Since that period, the practice and management of the parachute have been carried much farther by other aerial adventurers, and particularly by M. Garnerin, who has dared repeatedly to descend from the region of the clouds by that very slender machine. This ingenious Frenchman visited England during the short peace of 1802, and made four fine ascents in his balloon; in the last of which, September 21, he undertook the singular and desperate experiment of descending in a parachute. The ascent took place from St. George's Parade, North Audley-street, London, and he descended in a field near the Small-pox Hospital, Pancras. The balloon was of the usual sort, viz. of oiled silk, with a net, from which ropes proceeded, and were terminated in, or were joined to, a single rope at a few feet distance below the balloon. To this rope the parachute was fastened. The construction of the machine, with the mode of fastening, may be described as follows. It consisted in the first place of thirty-two gores of white canvas, formed into an hemispherical case of twenty-three feet diameter, at the top of which was a truck, or round piece of wood, ten inches broad, having a hole in its centre, admitting short pieces of tape to fasten it to the several gores of the canvas. Several ropes about thirty feet long, which proceeded from the edge of the parachute, terminated in a common joining, from which the shorter ropes proceeded; and to the extremities of these a circular basket was fastened, intended for the reception of the adventurer. Now the single rope, which has been said above to proceed from the balloon, passed through the hole in the truck in the centre of the parachute, and also through certain tin tubes which were placed one after the other in the place of the handle or stick of an umbrella, and was lastly fastened to the basket; so that when the balloon was in the air, by cutting the end of this rope next to the basket, the latter, with the attached parachute, would be separated from the balloon, and in falling downwards, would naturally be opened by the resistance of the air. The use of the tin tubes was, to let the rope slip off with greater certainty, and to prevent its becoming entangled with any of the other cordage, as also to keep the parachute at a distance from the basket. The above description will be better understood by referring to the Plate, in which the ascent and descent of M. Garnerin are shown in corresponding figures. The balloon began to be filled about two o'clock; there were thirty-six casks filled with iron filings and diluted sulphuric acid, for the production of the hydrogen gas; these communicated with three other casks, or general receivers, to each of which was fixed a pipe that emptied itself into the main tube attached to the

balloon. At six the operation of filling being completed, AER M. Garnerin placed himself in the basket, and the NAUTI whole machine and apparatus rose majestically amidst the acclamation of innumerable spectators. The weather was the clearest and pleasantest imaginable, the wind was gentle, and about west by south, and consequently the balloon moved slightly in the opposite direction. In less than ten minutes, the machine, with its attendant and appendages, had ascended to an immense height, and M. Garnerin in the basket was scarcely perceptible. Every eye was now directed to the adventurous aeronaut; in a moment the rope was 'cut, and the balloon and parachute separated from each other. Before the latter opened, it fell with a great velocity, and as soon as it was expanded, which took place a few moments after, the descent became more gradual, but still attended with a very fearful appearance, the whole apparatus vibrating like the pendulum of a clock, but in such large arcs that several times the parachute, and the basket with Garnerin, seemed to be nearly horizontal; the extent, however, of the vibrations diminished as he came nearer the ground, which he ultimately reached, as we have already said, in a field in St. Pancras, but with so much violence as to throw him on his face, by which accident he received some severe cuts and bled considerably. He seemed much agitated, and trembled excessively at the moment he was released from the basket. One of the stays of the parachute had given way, an untoward chcumstance which deranged the apparatus, and threatened the adventurer during the whole of his descent, with immediate destruction.

The voyages which we have hitherto detailed, were undertaken merely as matters of curiosity, and little of scientific research had yet been attempted by them. Philosophers, however, now became anxious to turn them to a more useful purpose, and to determine, by the means which they afforded, what circumstances attended the magnetic and electric action in the upper regions of the atmosphere; as also the proportions of the component parts of the air in places remote from the surface of the earth.

The first aerial voyage which can be said to have been made with the above views, was undertaken by Mr. Robertson and Lhoest, from Hamburgh, about the middle of July, 1803. The ascent having been accomplished, the aeronauts hovered for some time over the city; when, after throwing out some ballast, they rose to such a height, that the elasticity of the air distended the balloon so much that they were under the necessity of opening the valve and suffering some of the gas to escape, which issued from its confinement with a loud noise. The tension of the balloon being thus considerably lessened, they threw out more ballast, and ascended to such a height, that it was almost impossible to endure the cold that they experienced. Their teeth chattered, and Mr. Robertson's veins swelled, and the blood issued from his nose. His companion was otherwise affected, his head having swelled so much that he could not keep on his hat; they also both experienced a great numbness, which inclined them to sleep. Not being able any longer to endure this temperature, they descended slowly for about half an hour, and approached the earth over Badenburg, near Winsen on the Lube, where they intended to have alighted, but the inhabitants taking them for spectres fled with