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AËRO- the utmost consternation, taking with them their cattle. part of the earth the balloon at any time was hovering, A ERONALTICS. The aëronauts, fearing that this terror might be at the two following methods were employed.
NAUTICS. tended with serious consequences to them, after throw In an aperture made in the bottom of the car, there ing out part of their ballast, again ascended, and con• was fixed perpendicularly, an achromatic telescope, tinued their voyage, ultimately arriving at Wichten- which showed very distinctly those terrestrial objects beck, on the road to Zell.
over which the balloon happened to be, and to which When the balloon first rose, the atmosphere below side it directed its course. In the next place, two was very serene, but it was cloudy above; they ob- sheets of black paper were fixed together at right anserved, that as they ascended the heat decreased very gles, and suspended from the car with a piece of sensibly, and that they could look at the sun without thread, which was intended to indicate any variation being dazzled. The barometer, which before the ascent in the direction of the balloon, and was therefore called stood at 27 inches, fell to 14, where it appeared to be- the way wiser: it answered its purpose much betcome stationary; and the thermometer sunk to 4? be- ter than had been anticipated. At about a quarter low zero. Having, while thus situated, taken some past seven in the evening, when the barometer stood at refreshment, they ascended higher, viz. till the baro- 30 inches, and the centigrade thermometer at 19°, the meter fell to 124 inches; and at that height the cold machine ascended, and at 31 minutes past seven the out of the car was insupportable, although the ther- barometer had sunk to 29 inches, and the thermometer mometer was now only one degree below the freezing to 18°; the first cask was now filled with air, and six point. Here our adventurers were obliged to respire minutes after, when the barometer had fallen another very rapidly, and their pulsations became very quick. In inch, the second cask was opened and filled. At this this region, while the balloon was invisible to the earth, time, as the towns and villages were obscured by a fog, Mr. Robertson made the following experiments : the paper way wiser was thrown out, which indicated
1. Having let a drop of ether fall on a piece of glass, any variation in the direction of the balloon, as also it evaporated in four seconds.
its sinking and rising; for as soon as the machine fell, 2. He electrified by friction glass and sealing wax; the way wiser, as it was much lighter than the balloon, but these substances gave no signs of the accumulation and found more resistance in falling, appeared to fly up, of electric fluid that could be communicated to other and when the balloon rose, it sunk to the full length of bodies. The Voltaic pile, which, when the balloon was its thread; at other times it was found to hold a diagoset free from the earth, acted with its full force, gave 'nal direction, and in short pointed out with considerable only one-tenth part of its electricity.
accuracy, with the assistance of the compass needle, 3. The dipping needle seemed to have lost its mag- not only any variation in the motion, but the actual netic virtue, and could not be brought to that direction direction of the whole machine. which it had at the surface of the earth.
Having, at twenty-five minutes past eight, ascended 4. He struck with a hammer oxygenated muriate of to such a height that the barometer stood at twenty-six potash. The explosion occasioned a sharp noise, which, inches, another cask was filled with air; and soon though not very strong, was insufferable to the ear. afterwards another, when the barometer was at twentyIt is also to be observed, that though the aëronauts five inches; and the ame was done for every inch of spoke very loudly, they could only with great difficulty descent of the mercury. At about thirty minutes past hear each other.
nine, the barometer indicated twenty-two inches, and 5. At this height Mr. Robertson was not able to the thermometer 41°; at which time the voyagers saw extract any electricity from the atmospheric electro- the sun; it was about half obscured either by a fog or meter and condenser.
by the horizon, but they could not distinguish which. 6. In consequence of a suggestion from Professor At this period they commenced the following series of Helmbstadt, of Berlin, Mr. Robertson carried with experiments and observations. A piece of sealing-wax him two birds. The rarefaction of the air killed one rubbed with cloth, put in motion Bennet's electrometer. of them, and the other was unable to fly; it lay ex- The magnetic needle, which was taken for the purpose tended on its back, but Auttered with its wings. of examining the inclination, had been damaged; but
7. Water began to boil by means of a moderate de- in order to ascertain whether the magnetic power still gree of heat maintained with quick lime.
remained the same, as at the earth's surface, Mr. 8. According to observations made, it appeared that Sacharof placed a common magnetic needle, on a pin, the clouds never rise above 2000 toises; and it was and was surprised to find the north end rise, and cononly in ascending and descending through clouds, that sequently the south descend considerably, making an Mr. Robertson was able to obtain positive electricity. angle of ten or twelve degrees. This experiment being
The greatest height attained in this voyage is esti- repeated several times, both by this gentleman and mated at 2600 toises.
Mr. Robertson, the result was constantly the same; Mr. Robertson afterwards, viz, on the 30th of June, after descending, and at present, Mr. Sacharof obHubest
. 1804, ascended from Petersburgh with the academician serves, the same needle assumes a horizontal position. ali ini mend Sacharof: the aëronauts, taking with them, for the At this height the aeronauts did not experience the
purpose of making the different experiments proposed slightest inconvenience, except that their ears were by the academy, twelve exhausted flasks, a barometer benumbed with the cold. My pulse,” says Mr. and attached thermometer, a detached thermometer, Sacharof, “ beat as on the earth, that is, eighty-two two electrometers, sealing wax and sulphur, a compass times in a minute, and I breathed twenty-two times in and magnetic needle, a seconds watch, a bell, a speak- the same interval, as is usual with me. In a word, I was ing trumpet, a prism of crystal, and unslaked lime, and exceedingly tranquil and cheerful, and experienced no a few other apparatus for chemical and philosophical change or uneasiness.” At that time there were white experiments.
clouds a great way above the balloon, but the heavens In order to ascertain with some precision, over what in general were clear and bright, notwithstanding
AFRO- which, however, they could observe no stars. Mr. mometers, hygrometers, and electrometers, MM. Biot Afiro.
voyage all night, in order that they might see the sun dipping needle, with another fine needle carefully mag-
In order that the descent might be made as safely 30·13 inches English; Reaumur's thermometer at 139.2,
We have given the detail of the two preceding as clouds had in this situation a similar blueish tint to that cents, not in consequence of the importance of the which they exhibit from the surface of the earth, while observations or experiments that were performed in their upper surface, full of small eminences and unthem, but because they seem to have been the first dulations, presented to the aëronauts the appearance of aerial excursions made purely with a view to philoso- a vast plain covered with snow. At this time their altiphical research ; and moreover, because in some re- tude, computed according to Laplace's barometrical forspects the inferences to be drawn from them are at mulæ, was 2000 metres, or about 6500 English feet, and variance with the deductions formed from the experi- here their observations and experiments first commenced. ments performed in the two following ascents; the first On attempting to make their needle oscillate, they Experine by Biot and Gay-Lussac, and the second by the latter discovered that the balloon had a slight rotatory motion, on the philosopher alone.
which made a continual variation between the position magiet.
vatoire des Arts, on the 24th of August, 1804, their prevented them from observing the point where the
and the decomposition of water. All this, M. Biot obBesides the usual provisions of barometers, ther- serves, might have been foreseen, since it is known the
sëro. action of this pile does not cease even in a vacuum. electrometer; and it was found to be resinous. This AËRO. MALTICS. Their computed height was about 2724 metres. At this experiment was performed twice at the same moment;
NAUTICS. elevation the animals they carried with them seemed to first by destroying the atmospheric electricity by the Dectric er- suffer no inconvenience from the rarety of the air; a influence of the vitreous electricity of the electrophorus,
violet bee, which they now sent off, flew quickly away and secondly by destroying the vitreous electricity ex-
The balloon still continued its rotatory, or rather its agreeable to results before known; but the difference
when another vibration began in the opposite direction. Fahrenheit's scale, the thermometer indicating at the Nagetic The voyagers took advantage of these momentary ces same moment at the observatory no more than 631°. es mirats sations to make their magnetic experiments; but as this Another remarkable fact given by these observations Ilumidity. Filateite stationary state continued only for a few moments, it was is, that the hygrometer always advanced towards dry
not possible to observe even so few as twenty conse ness as the balloon rose in the atmosphere, and that in cutive vibrations as on the earth. They were, there. descending it gradually returned to humidity. At the time fore, under the necessity of being satisfied with ten, or the ascent took place, this instrument indicated 800.8 even five, taking at the same time great care not to at 16°.5 of the centigrade thermometer, and at the eleagitate the car; for the slightest motion, even of the vation of 4000 metres, though the temperature was hand in writing down their observations, was found only 100.5, it gave no more than 30°. The air is sufficient to turn them aside. They made ten series consequently much drier in the upper regions than at of observations of this kind at different altitudes, from the surface of the earth ; this at least is the conclusion 2897 metres to 3977 metres, which in all amounted to that M. Biot wishes to deduce from the above results, 65 oscillations, and the mean of the whole, and of each but we have seen the justness of it questioned. It has set separately, gave very nearly the same result as their been observed, that the indications of the hygroscope observations on the earth's surface. From these ob- depend on the relative attraction for humidity possessed servations, M. Biot concludes, that the magnetic pro- by the substances employed, and the medium in which perly experiences no appreciable diminution from the sur it is immersed. But air has its disposition to retain face of the earth to the height of 4000 metres, or 15748 moisture, always augmented by rarefaction, and conseEnglish feet; its action within these limits being con- quently such alteration alone must materially affect the stantly manifested by the same effect, and according to the hygroscope. Such are the results of this, which has same law. With respect to the inclination of the mag generally been considered the most scientific ascent netic needle, M. Biot observes, that he was not able to that had yet been made; and having accompanied the observe it with so much accuracy, and therefore cannot aëronauts thus far on their voyage, we propose to assert positively that it experiences no variation ; al- attend them in their descent, which took place under though he thinks it very probable that it does not, its the following circumstances : horizontal force having undergone no variation. At The ballast being very nearly all expended, they re- Descent. least, if any such did take place, it was very inconsi- solved to descend by permitting part of the hydrogen derable, because the magnetic bars, brought into equi- gas to escape.
When they had descended to within librium before their departure, retained their hori 4000 feet of the earth's surface, the balloon entered the zontality during their whole journey, which would not stratum of clouds spoken of above, extending horizonhave been the case had the force which tends to in tally, but with the surface heaved into gentle swells. cline them experienced any sensible change.
When they reached the ground, no people were near The declination of the needle was also another object to stop the machine, in consequence of which they of the research of these philosophers, but the weather, were dragged in the car to some distance along the and the disposition of the apparatus, did not permit fields. From this aukward and even dangerous situathem to come to any decided conclusion on this point; tion they could not extricate themselves, without disthey seem, however, to incline here also to the opinion charging all the remaining gas. that it does not vary in any sensible manner.
It has been reported that M. Biot, though a man of M. Biot and Gay-Lussac had now ascended to the activity, and apparent firmness, was so overpowered by ents of the height of 13,385
feet, but had not yet made many of the alarm of their descent, as to lose, for the time, the da vybere. their electric experiments, their attention having been entire possession of himself, notwithstanding, in his
almost entirely engrossed with their observations on the memoir, presented a few days afterwards to the Instimagnet, which was the principal object they had in view. tute, he proposed to go up again, if such were the wish In order now to try the apparatus, a wire was let down of that learned body. 240 feet in length, which being insulated, electricity was He did not, however, ascend a second time, but at Lussac's seextracted from its upper extremity, and applied to the the desire of several philosophers in Paris, M. Gay-cond ascent.
AERO. Lussac made another voyage alone on the 15th of whole atmosphere below him, through which distant Ali
ground, at about forty minutes past nine o'clock in the had ascended to the height of 3032 metres, or about
Table of the Observations of Mr. Gay-Lussac, in his ascent on the 15th of September, 1804.
AFRO If now we cast our eye over the table of results, it he experienced no other direct inconvenience from his A ÜRO-
law in regard to the corresponding heights, which, our whole day with a slight head-ache, brought on by pre-
But if we
The ballast being now reduced to 33 pounds, and Descent, consider only the degrees of the thermometer which the balloon completely distended, it began to drop; form a decreasing series, we shall find a more regular and M. Gay-Lussac, therefore, only sought to regulate law; thus the temperature at the earth being 27.75, its descent. It subsided very gently, at the rate of and at the height of 3691, 89.5, if we divide the dif- about a mile in eight minutes, and in little more than ference of the heights by that of the temperatures, we half an hour the anchor touched the ground, and inshall first obtain 191•7 metres, or 98-3 toises of ele- stantly secured the car. The voyager alighted with great vation for each lowering of one degree of temperature. ease near the hamlet of St. Gourgon, about 16 miles Performing the same operation for the temperatures north-west of Rouen. As soon as he reached Paris, he 50-25 and 00.5, as well as for those of 0°.0 and—9o.25, hastened to the laboratory of the Polytecnic School with we shall find in both cases 241.6 metres, or 72.6 toises his flasks containing the air of the higher regions, and of elevation for each degree of temperature, which proceeded to analyse it in the presence of Thenard and seems to indicate, that towards the surface of the earth Gresset. When opened under water, the fuid rushed the heat follows a less decreasing law than in the upper into the vessels, and apparently half filled their capacity. parts of the atmosphere, and at greater heights it fol- The transported air was found, by a very delicate analows a decreasing arithmetical progression. The lowest lysis, to contain exactly the same proportions as that point of temperature observed was -90.25, correspond- collected near the surface of the earth, every 1000 Analysis of ing to 140.9 of Fahrenheit's thermometer; the corres- parts holding 215 of oxygen. From concurring obser- the air. ponding height being then equal to 23040 English vations, therefore, we may conclude that the atmosphere feet above the earth's surface, or 4 miles.
is essentially the same in all situations. The hygrometer had a very remarkable progress. We have given the details of the two preceding At the surface of the earth it was only 574", while, at ascents at considerable length, in consequence of the the height of 3030 metres, it marked 62°. From this scientific researches the aëronauts had in view, and
it continually fell, till the balloon reached the which they accomplished, if not entirely in such a height of 5267 metres, where it indicated 27, and manner as to satisfy the eager curiosity of philosophers, thence to the height of 6884 metres it gradually rose at least in a way highly creditable to themselves, when to 344°. If we wish, from these results, to determine we consider all the difficulties of their situations. The the law of the quantity of water dissolved in the air at length of detail, however, to which we have extended different elevations, it is evident that attention must be our remarks on these scientific voyages, renders it nepaid to the temperature, and, by adding this considera- cessary to pass slightly over others performed merely tion, it will be found to follow a rapidly decreasing to gratify the curiosity of spectators, although many progression.
of these even were attended with circumstances highly With respect to the magnetic operations, all that curious and interesting to the general reader. We can be concluded from them is, that it seems highly shall confine our remarks only to the following: probable that no sensible difference in the action of the On the 7th of April, 1806, M. Mosment, an expe- Fatal ascent magnetic force is observable at the greatest heights to rienced aëronaut, undertook an aërial voyage from Lisle ; of Mosment, which we can ascend, and some doubt is certainly he ascended at noon, waving a fiag decorated with the thrown, from the results of this and the preceding imperial eagle, amid the shouts of the assembled specvoyage, on the deductions drawn from that of Messrs. tators. The commencement of his career was Sacharof and Robertson.
rapid, as to carry him, in a very short time, beyond the The two air flasks to which we have alluded were vision of the crowd. During his ascent he dropped a apened, one at the height of 21460 feet, and the other dog, attached to a parachute, which came safely to the at 21790 feet, when the air rushed into them through ground. About one o'clock something was observed the narrow aperture with a whistling noise; having slowly descending through the atmosphere, which properly stopped the orifices again, the balloon soon proved, on its fall, to be the flag that M. Mosment had after attained its greatest height, 41 English iniles, carried with him. Very soon after, a murmur cireuwhen the barometer indicated only 12.95 inches. lated through the crowd, that the body of the unfortu
From this stupendous height M. Gay-Lussac still saw nate adventurer was discovered in one of the fosses of clouds at a considerable height above, but none below, the city, lifeless, and covered with blood, which proved although the atmosphere had a dull misty appearance, but too correct. The balloon reached the ground on the which destroyed its transparent quality; the limit, same day, at the distance of twenty-five leagues from therefore, fixed by M. Sacharof for the greatest height Lisle. The car contained nothing except an unloaded of the clouds is obviously erroneous.
pistol, a little bread, and a piece of meat. M. Garnerin While occupied with experiments at this enormous ascribes this melancholy disaster to the extreme shalelevation, M. Gay-Lussac, though well cloathed, began lewness of the car, and the too great distance between to suffer from excessive cold, and his hands, by conti- the cords which attached it to the balloon; and is of nual exposure, grew benumbed. He felt likewise a opinion that M. Mosment, in leaning over the car to difficulty in breathing, and his pulse and respiration drop the animal, had lost his balance and was thus were much quickened. His throat became so parched precipitated to the earth. that he could scarcely swallow a morsel of bread; but Another interesting voyage was that undertaken by