PART III.

Scientific Experiments--Applications of Ballooning.

CHAPTER I. Experiments of Robertson, Lhoest,

Saccarof, &c.

Robertson is regarded by many as a sort of mountebank; yet such men as Arago have put themselves to the trouble of examining the aerostatic feats of this aeronaut, and of examining the results of his observations.

"The savant Robertson," says Arago, "performed at Hamburg on the 18th of July, 1803, with his countryman, Lhoest, the first aeronautic voyage from which science has been able to draw useful deductions. The two aeronauts remained suspended in the air during five hours, and came down near Hanover, twenty-five leagues from the spot from which they set off."

The first time that Robertson appears in the annals of aerostation is in 1802, on the occasion of the sale of the balloon used at the battle of Fleurus, of which mention will be made in the chapter on military aerostation. But three years previously he had been instructed to make a balloon of an original form, which should ascend in honour of the Turkish ambassador at the garden of Tivoli. The fete was completely successful. Turks, Chinese, Persians, and Bedouins will always be welcome, as on this occasion, at Paris, appearing as they do only at rare intervals, and for a short time.

The fete took place on the 2nd of July. Robertson presented himself at the house of Esseid-Ali, to obtain his autograph. The Turkish ambassador willingly granted the request, and wrote his name in letters, each of which was two inches in height, on a sheet of paper. He then offered the aeronaut coffee and comfits, and promised to be present to witness the balloon ascent. His name was painted in large characters on a balloon fifteen feet in diameter, and on the form of which was the figure of a crescent. The experiment delighted the ambassador, and was well received by the public. Jacques Garnerin, when he came to make his debut as an aeronaut, made an attempt with the parachute, the following August, at the garden of the Hotel de Biron. The ambassador was asked to honour the fete, but he declined, saying that he had "made up his mind that man was not intended

for flying--Mahomet had not so willed it."

Of one of Robertson's more interesting ascents he himself has left us the following sketch:--

"I rose in the balloon at nine a.m., accompanied by my fellow-student and countryman, M. Lhoest. We had 140 lbs. of ballast. The barometer marked twenty-eight inches; the thermometer sixteen degrees Reaumur. In spite of some slight wind from the north-west, the balloon mounted so perpendicularly that in all the streets each of the spectators believed we were mounting straight up above his head. In order to quicken our ascent I discharged a parachute made of silk, and weighted in a way to prevent oscillations. The parachute descended at the rate of two feet per second, and its descent was uniform. From the moment when the barometer began to sink we became very careful of our ballast, as we wished to test from experience the different temperatures through which we were about to pass.

"At 10.15, the barometer was at nineteen inches, and the thermometer at three above zero. We now felt all the inconvenience of an extremely rarefied atmosphere coming upon us, and we commenced to arrange some experiments in atmospheric electricity. Our first attempts did not succeed. We threw over part of our ballast, and mounted up till the cold and the rarefaction of the air became very troublesome. During our experiments we experienced an illness throughout our whole system. Buzzing in the cars commenced, and went on increasing. The pain we felt was like that which one feels when he plunges his head in water. Our chests seemed to be dilated, and failed in elasticity. My pulse was quickened, M. Lhoest's became slower; he had, like me, swelled lips and bleeding eyes; the veins seemed to come out more strongly on the hands. The blood ran to the head, and occasioned a feeling as if our hats were too tight. The thermometer continued to descend, and, as we ascended, our illness increased, and we could with difficulty keep awake. Fearing that my travelling companion might go to sleep, I attached a cord to my thigh and to ]his, and we held the extremities of the cord in our hands. Thus trammelled, we had to commence the experiments which I had proposed to make.

"At this elevation, the glass, the brimstone, and the Spanish wax were

not electrified in a manner to show any signs under friction--at least, I obtained no electricity from the conductors or the electrometer.

"I had in my car a voltaic pile, consisting of sixty couples--silver and zinc. It worked very well on the occasion of our departure from the earth, and gave, without the condenser, one degree to the electrometer. At our great elevation, the pile gave only five-sixths of a degree to the same electrometer. The galvanic flame seemed more active at this elevation than on the earth.

"I took two birds with me on coming into the balloon--one of these was now dead, the other appeared stupefied. After having placed it upon the brink of the gondola, I tried to frighten it to make it take to flight. It moved its wings, but did not leave the spot; then I left it to itself, and it fell perpendicularly and with great rapidity. Birds are certainly not able to maintain themselves at such elevations.

"It is notable that the atmosphere, which was of a perfect purity near the earth, was grey and misty above our heads, and the beautiful blue sky seen from the surface did not exist for us, although the weather was calm and serene, and the day the most beautiful that could be. The sun did not seem dazzling to us, and its heat was diminished owing to our elevation.

"At half-past eleven, the balloon was no longer visible from Hamburg. The heavens were so pure beneath us that everything was distinctly seen by us, though very much diminished by distance. At 11.40, the town of Hamburg seemed only a red point in our eyes; the Elbe looked like a straight ribbon. I wished to make use of an opera-glass, but what surprised me was that when I lifted it up it was so cold that I had to wrap my handkerchief around it to enable me to hold it.

"Not being able to support our position any longer, we descended, after having used up much gas and ballast. Our descent caused that degree of terror among the inhabitants which the size of our balloon was calculated to inspire in a country where such machines had never before been seen. We descended above a poor village called Radenburg, a place amid the heaths of Hanover. Our appearance caused great alarm, and even the beasts of the field fled from us.

"While our balloon rapidly approached the earth, we waved our hats

and flags, and shouted to the inhabitants, but our voices only increased their terror. The villagers rushed away with cries of terror, leaving their herds, whose bellowings increased the general alarm. When the balloon touched the ground, every man had shut himself up in his own house. Having appealed in vain, and fearing that the villagers might do us some injury, we resolved to re-ascend.

"In making this second ascent, we threw over all our ballast; but in this we were imprudent, for after sailing about at a great height, and having lost much gas, I perceived that our descent would be very rapid, and to provide against accident, I gathered together all the instruments, the bread, the ropes, and even such money as we had with us, and placed them in three sacks, to which I attached a rope of a hundred feet in length. This precaution saved us a shock. The weight, amounting to thirty pounds, reached the ground before us, and the balloon, thus lightened, came softly to the ground between Wichtenbech and Hanover, after having run twenty- five leagues in five and a half hours."

After this ascent Robertson became acquainted with some savants of Hamburg, and amongst others with Professor Pfaff, who was interested in aerial travelling as a means of settling certain meteorological problems. Some days after Robertson's ascent, the professor wrote to him--

"You speak of a certain height at which the hydrogen gas will find itself in equilibrium in the air of the atmosphere. I believe that this height is the extremity of the atmosphere itself; for as the gas has an elasticity much greater than that of the air, it will go on dilating as it mounts into the higher regions of the atmosphere, and its specific weight will diminish as the weight of atmospheric air diminishes; and it will not cease to mount until it rises above the atmosphere itself, if two conditions be completely fulfilled--1, the condition that the gas may be allowed to dilate without leaving the balloon as it rises; 2, the condition that the gas shall not be allowed to mix at all with the atmospheric air."

Another ascent was arranged for the 14th of August, in which Robertson was to be accompanied by the professor, but the latter, yielding to the entreaties of his family, did not go. "I went up with my friend Lhoest," says Robertson, "at forty-two minutes past twelve midday. In a

minute or two we rose up between two masses of cloud, which seemed to open up and offer us a passage. The upper surfaces of these clouds are not uniformly level, like the under sides seen from the earth, but they are of a conical or pyramidal shape. These imposing masses seem to precipitate themselves upon the earth, as if to engulf it, but this optical illusion was due to the apparent immobility of the balloon, which at the moment was rising at the rate of about twenty feet per second.

"The fear of losing the view of the Baltic, which we perceived between the clouds at intervals, obliged us to renounce the project of rising as high as on the last occasion. The barometer was at fifteen inches, and the thermometer one degree below zero, when I let off two pigeons.

"One descended in a diagonal direction, its wings half open but not moving, with a swiftness which seemed that of a fall. The other flew for an instant, and then placed itself upon the car, and did not wish to quit us. Acting on the hint of Dr. Reimarus, I tried the same experiment with butterflies, but the air was too much rarefied for them; they attempted in vain to raise themselves by their wings, but they did not forsake the car.

"The wind continuing to carry me towards the sea, I resolved to bring my observations to an end. I effected my descent in a meadow, near the village of Rehorst, in Holstein, after having run sixteen leagues from France in sixty-five minutes."

At the commencement of the year 1804, Laplace, at the Institute, proposed to take advantage of the means offered by aerostation to verify at great heights certain scientific points--as, for example, those which concern magnetism. This proposition was made at a favourable time, and was, so far, carried out in the best possible way. The aeronauts who were appointed to carry out the expedition were Biot and Gay-Lussac, the most enthusiastic aeronauts of the period.

The following is their report:--

"We observed the animals we had with us at all the different heights, and they did not appear to suffer in any manner. For ourselves, we perceived no effect any more then a quickening of the pulse. At 10,000 feet above the ground we set a little green-finch at liberty. He flew out at once, but immediately returning, settled upon our cordage; afterwards,

setting out again, he flew to the earth, describing a very tortuous line in his passage. We followed him with our eyes till he was lost in the clouds. A pigeon, which we set free at the same elevation, presented a very curious spectacle. Placed at liberty on the edge of the car, he remained at rest for a number of instants, as if measuring the length of his flight; then he launched himself into space, flying about irregularly, as if to try his wings. Afterwards he began his descent regularly, sweeping round and round in great circles, ever reaching lower, until he also was lost in the clouds."

As to the voyagers themselves, this is how they speak of their situation at the height of 3,000 yards:--

"About this elevation we observed our animals. They did not appear to suffer from the rarity of the air, yet the barometer was at twenty inches eight lines.. We were much surprised that we did not suffer from the cold; on the contrary, the sun warmed us much. We had thrown aside the gloves which had been put on board, and which were of no use to us. Our pulses were very quick; that of M. Gay-Lussac, which is 62 in the minute on ordinary occasions, now gave 80; and mine, which is ordinarily 89, gave

111. This acceleration was felt by both of us in nearly the same proportion. Nevertheless, our respiration was in no way interfered with, we experienced no illness, and our situation seemed to us extremely agreeable."

The following is their report to the Galvanic Society--

"We have known for a long time that no animal can with safety pass into an atmosphere much more dense or much more rare than that to which it has been accustomed. In the first case it suffers from the outer air, which presses upon it severely; in the second case there are liquids or fluids in the animal's body which, being less pressed against than they should be, become dilated, and press against their coverings or channels. In both cases the symptoms are nearly the same--pain, general illness, buzzing in the ears, and even haemorrhage. The experience of the diving- bell has long made us familiar with what aeronauts suffer. Our colleague (Robertson), and his companion, have experienced these effects in great intensity. They had swelled lips, their eyes bled, their veins were dilated, and, what is very remarkable, they both preserved a brown or red tinge

which astonished those that had seen them before they made the ascent. This distension of the blood-vessels would necessarily produce an inconvenience and a difficulty in the muscular action."

CHAPTER II. Ascent of M. Gay-Lussac Alone-- Excursions of MM. Barral and Bixio.

Respecting this ascent, Arago states that M. Gay-Lussac has reduced to their proper value the narratives of the physical pains which aeronauts say they suffer in lofty aerial ascents.

M. Gay-Lussac says:--"Having arrived at the most elevated point of my ascent, 21,000 feet above sea level, my respiration was rendered sensibly difficult, but I was far from experiencing any illness of a kind to make me descend. My pulse and my breathing were very quick; breathing very frequently in an extremely dry atmosphere, I should not have been surprised if my throat had been so dry as to make it painful to swallow bread."

After having finished his observations, which referred chiefly to the magnetic needle, with all the tranquillity of a doctor in his study, Gay- Lussac descended to the earth between Rouen and Dieppe, eighty leagues from Paris.

After the names of Robertson, Gay-Lussac, and Biot, science has registered those of Barral and Bixio, two men whose aeronautic achievements have enriched meteorology with more important discoveries, perhaps, than any we have yet mentioned.

These gentlemen had conceived the project of rising by means of a balloon to a great height, in order to study, with the assistance of the very best instruments in use in their day, a multitude of phenomena then imperfectly known. The subjects to which they were specially to direct their attention, were the law of the decrease of temperature in progress upwards, the discovery of whether the chemical composition of the atmosphere is the same throughout all its parts, the comparison of the strength of the solar rays in the higher regions of the atmosphere and on the surface of the earth, the ascertaining whether the light reflected and transmitted by the clouds is or is not polarised, &c.

All the preparations having been made in the garden of the Observatory at Paris, the ascent took place on the 29th of June, 1850, at

10.27 a.m., the balloon being filled with hydrogen gas. The first ascent was a signal failure. It was found that the weather being bad, the envelope of the balloon was torn in several places, and had to be mended in all haste. Immediately preceding the moment of ascent, a torrent of rain fell. But the voyagers were determined to ascend. They placed themselves in the car, and, when thrown off from the fastenings, they rose through the air with the speed of an arrow. The height to which the balloon reached made it suddenly dilate, and the network, which was much too small, was stretched to the utmost. The balloon was forced down upon them by the dilation, and one of them, in the endeavour to work the valve, made a rent in the lower part of the globe, from which the gas escaping almost over the heads of the travellers, nearly choked them. The escape of the gas had the usual result--the balloon descended rapidly, and fell in a vineyard near Lugny, where they were found by the peasants holding on to the trees by their legs and arms, and thus attempting to stop the horizontal advance of the car. They had risen to the height of over 17,000 feet, and they had descended from this height in from four to five minutes.

For all practical purposes, the ascent was a failure, and the aeronauts immediately commenced preparations for a new voyage, which took place a month afterwards. They rose to very great altitudes, but experienced no illness from the rarefied air. M. Bixio did not feel the sharp pains in the ears from which he had suffered on the former occasion. They passed through a mass of cloud 15,000 feet in thickness, and they had not yet passed quite through it, when at the height of over 21,000 feet from the ground, they began to descend, their descent being caused by a rent in the envelope of the balloon, from which the gas escaped. They might, in throwing out the last of their ballast, have, perhaps, prolonged for a little their sojourn in space, but the circumstances in which they were placed did not permit them to make many more scientific observations than those they had made, and thus they were obliged to submit to their fate. When they had reached their greatest height, there seemed to open up in the midst of the vaporous mass a brilliant space, from which they could see the blue of heaven. The polariscope, directed towards this region, showed an internal polarisation, but, when pointed to the side where the mist still

prevailed, there was no polarisation.

An optical phenomenon of a remarkable kind was witnessed when the voyagers had attained their highest point. They saw the sun through the upper mists, looking quite white, as if shorn of its strength; and, at the same time, below the horizontal plane, below their horizon, and at an angular distance from the plane equal to that of the sun above it, they saw a second sun, which resembled the reflection of the actual sun in a sheet of water. It is natural to suppose that the second sun was formed by the reflection of the sun's rays upon the horizontal faces of the ice crystals floating in this high cloud.

CHAPTER III. Ascents of the Mssrs. Welsh, Glaisher and Coxwell.

The most recent balloon ascents in England deserving attention have been undertaken for scientific objects, and in this country, more than in any other, it may be said that the conquest of the air has been made to serve a practical end.

In July, 1852, the Committee of the Kew Observatory resolved to undertake a number of balloon voyages. This resolution was approved of by the British Association for the Advancement of Science, and the necessary instruments for making a number of meteorological observations were prepared. The balloon employed was that of Mr. Green, who was accompanied in his ascents by Mr. Welsh. The greatest height to which Mr. Welsh rose was on the fourth ascent which took place on the 10th of November, 1852. The balloon rose 22,930 feet, and the lowest temperature observed was 26 degrees below zero.

It is to Mr. Glaisher and Mr. Coxwell, however, that the highest honours of scientific aerostation belong. The ascents made by these gentlemen--Mr. Glaisher being the scientific observer, and Mr. Coxwell the practical aeronaut--have become matters of history. Not only did they, in the course of a large number of ascents undertaken under the auspices of the British Association, succeed in gathering much valuable meteorological information, but they reached a greater height than that ever gained on any previous or subsequent occasion, and penetrated into that distant region of the skies in which it has been satisfactorily proved that no life can be long maintained. It was on the 5th of September, 1862,that Mr. Glaisher and Mr. Coxwell made the famous ascent in which they reached the greatest height ever attained by an aeronaut, and were so nearly sacrificed to their unselfish daring. Mr. Glaisher has given an admirable account of this ascent, which took place from Wolverhampton. He says:--"Our ascent had been delayed, owing to the unfavourable state of the weather. It commenced at three minutes past one p.m., the temperature of the air being 59 degrees, and the dew-point 48 degrees. At

the height of one mile the temperature was 41 degrees and the dew-point 38 degrees. Shortly after wards clouds were entered of about 1,100 feet in thickness. Upon emerging from them at seventeen minutes past one, I tried to take a view of their surface with the camera, but the balloon was ascending too rapidly and spiraling too quickly to allow me to do so. The height of two miles was reached at twenty-one minutes past one. The temperature of the air had fallen to 32 degrees and the dew-point to 26 degrees. The third mile was passed at twenty-eight minutes past one, with an air temperature of 18 degrees, and a dew-point of 13 degrees. The fourth mile was passed at thirty-nine minutes past one, with an air temperature of 8 degrees, and a dew-point of minus 6 degrees and the fifth mile about ten minutes later, with an air temperature minus 5 degrees, and a dew-point minus 36 degrees.

"Up to this time I had experienced no particular inconvenience. When at the height of 26,000 feet I could not see the fine column of the mercury in the tube; then the fine divisions on the scale of the instrument became invisible. At that time I asked Mr. Coxwell to help me to read the instruments, as I experienced a difficulty in seeing them. In consequence of the rotary motion of the balloon, which had continued without ceasing since the earth was left, the valve line had become twisted, and he had to leave the car, and to mount into the ring above to adjust it. At that time I had no suspicion of other than temporary inconvenience in seeing. Shortly afterwards I laid my arm upon the table, possessed of its full vigour; but directly after, being desirous of using it, I found it powerless. It must have lost its power momentarily. I then tried to move the other arm, but found it powerless also. I next tried to shake myself, and succeeded in shaking my body. I seemed to have no legs. I could only shake my body. I then looked at the barometer, and whilst I was doing so my head fell on my left shoulder. I struggled, and shook my body again, but could not move my arms. I got my head upright, but for an instant only, when it fell on my right shoulder; and then I fell backwards, my back resting against the side of the car, and my head on its edge. In that position my eyes were directed towards Mr. Coxwell in the ring. When I shook my body I seemed to have full power over the muscles of the back, and considerable power over

those of the neck, but none over my limbs. As in the case of the arms, all muscular power was lost in an instant from my back and neck. I dimly saw Mr. Coxwell in the ring, and endeavoured to speak, but could not do so; when in an instant intense black darkness came over me, and the optic nerve lost power suddenly. I was still conscious, with as active a brain as whilst writing this. I thought I had been seized with asphyxia, and that I should experience no more, as death would come unless we speedily descended. Other thoughts were actively entering my mind when I suddenly became unconscious, as though going to sleep. I could not tell anything about the sense of hearing: the perfect stillness of the regions six miles from the earth--and at that time we were between six and seven miles high--is such that no sound reaches the ear. My last observation was made at 29,000 feet, about fifty-four minutes past one. I suppose two or three minutes elapsed between my eyes becoming insensible to seeing the fine divisions and fifty-four minutes past one, and that other two or three minutes elapsed before I became unconscious; therefore I think that took place about fifty-six or fifty-seven minutes past one. Whilst powerless I heard the words 'temperature,' and 'observation,' and I knew Mr. Coxwell was in the car, speaking to me, and endeavouring to rouse me; and therefore consciousness and hearing had returned. I then heard him speak more emphatically, but I could not speak or move. Then I heard him say, 'Do try; now do!' Then I saw the instruments dimly, next Mr. Coxwell, and very shortly I saw clearly. I rose in my seat and looked round, as though waking from sleep, and said to Mr. Coxwell, 'I have been insensible.' He said, 'Yes; and I too, very nearly.' I then drew up my legs, which had been extended out before me, and took a pencil in my hand to note my observations. Mr. Coxwell informed me that he had lost the use of his hands, which were black, and I poured brandy over them. I resumed my observations at seven minutes past two. I suppose three or four minutes were occupied from the time of my hearing the words 'temperature' and 'observation,' until I began to observe. If so, then returning consciousness came at four minutes past two, and that gives about seven minutes of total insensibility. Mr. Coxwell told me that in coming from the ring he thought for a moment that I had laid back to rest myself; that he spoke to me

without eliciting a reply; that he then noticed that my legs projected, and my arms hung down by my side. That my countenance was serene and placid, without earnestness or anxiety, he had noticed before going into the ring. It then struck him that I was insensible. He wished then to approach me, but could not, and he felt insensibility coming over himself. He became anxious to open the valve, but, in consequence of having lost the use of his hands, he could not; and ultimately he did so by seizing the cord with his teeth and dipping his head two or three times. No inconvenience followed our insensibility. When we dropped it was in a country where no accommodation of any kind could be obtained, so that we had to walk between seven and eight miles. At the time of ceasing our observations the ascent was at the rate of 1,000 feet per minute, and on resuming observations the descent was at the rate of 2,000 feet per minute. These two positions must be connected, having relation to the interval of time which elapsed between them; and they can scarcely be connected at a point less than 36,000 or 37,000 feet high. Again, a very delicate minimum thermometer was found to read minus 12 degrees, and that reading would indicate an elevation exceeding 36,000 feet. There cannot be any doubt that the balloon attained the great height of seven miles--the greatest ever reached. In this ascent six pigeons were taken up. One was thrown out at three miles. It extended its wings, and dropped like a piece of paper. A second at four miles, and it flew with vigour. A third between four and five miles, and it fell downwards. A fourth was thrown out at four miles in descending, and it alighted on the top of the balloon. Two were brought to the ground. One was dead, and the other was ill, but recovered so as to fly away in a quarter of an hour."

The results gathered by Mr. Glaisher from his numerous ascents are very interesting. He found that in no instance did the temperature of the air decrease uniformly with the increase of height. In fact, the decrease in the first mile is double that in the second, and nearly four times as great as the change of temperature in the fifth mile. The distribution of aqueous vapour in the air is no less remarkable. The temperature of the dew-point on leaving the earth decreases less rapidly than the temperature of the air; so that the difference between the two temperatures becomes less and less,

till the vapour or cloud plane is reached, when they are usually together, and always most nearly approach each other, and that point is usually at about the height of one mile. On leaving the upper surface of cloud, the dew point decreases more rapidly than the air, and at extremely high situations the difference between the two temperatures is wonderfully great, indicating an extraordinary degree of dryness, and an almost entire absence of water. Under these circumstances, the presence of cirrus clouds far above this dry region, apparently as much above as when viewed from the earth, is very remarkable, and leads to the conclusion that they are not composed of water.

In the propagation of sound, M. Glaisher made many curious experiments. In one ascent (July 17th) he found, when at a distance of 11,800 feet above the earth, that a band was heard; at a height of 22,000 feet, a clap of thunder was heard; and at a height of 10,070 feet, the report of a gun was heard. On one occasion, he heard the dull hum of London at a height of 9,000 feet above the city, and on another occasion, the shouting of many thousands of persons could not be heard at the height of 4,000 feet.

CHAPTER IV. Balloons Made Useful in Warfare.

Wars of the French Republic--Company of "Ballooneers"--Battle of Fleurus--The Balloons of Egypt--Napoleon--Modern Services War in Italy--War in America--Conclusion.

We will conclude our work with a glance at aerostation as applied to warfare. Scarcely had the first ascents astonished the world, than the more adventurous spirits began to use the new discovery for a thousand purposes directly useful to man. The first point of view in which aerostation was regarded, was in that of its practical utility If one refers to the pre-occupations of the time--to the great events then occurring in the history of France, one will easily understand that the Committee of Public Safety soon thought of employing balloons in the observation of the forces and the movements of hostile troops. In 1794, the idea was practically carried out, and the French armies were provided with two companies of aeronauts. The command of one of these companies was given to Captain Coutelle, a young physicist of great talent, who rendered memorable services at the battle of Fleurus. The balloons were not thrown free, but were retained attached by means of long cords. In this way they took up, so to speak, aerial posts of observation. Placed in his car, the captain transmitted his instructions to his men below by means of coloured flags. Coutelle has left us a lively narrative of certain incidents connected with one of the grand days of the old Republic. He had been commissioned by the Committee of Public Safety to go to Maubeuge, where Jourdan's army was encamped, and to offer him the use of his balloon. The representative to whom the young doctor presented his commission, knew nothing about balloons, and not being able to understand the order of the Committee of Public Safety, it suddenly dawned upon him that Coutelle, with his trumpery forgery about balloons, was nothing else than a spy, and he was about to have him shot. The genuineness of the order from the Committee, however, was proved, and Coutelle's case was listened to.

"The army was at Beaumont," says Coutelle, "and the enemy, placed at a distance of only three miles, could attack at any moment. The general told me this fact, and engaged me to return and communicate it to the

Committee. This I did. The Commission then felt the necessity of making an experiment with a balloon that could raise two persons, and the minister placed at my service the garden and the little mansion of Meudon. Many of the members of the Commission came to witness the first ascent of a balloon held in hand, like a kite, by means of two cords. The Commissioners ordered me to place myself in the car, and instructed me as to a number of signals which I must repeat, and observations which I must make. I raised myself to the full length of the cord, a height of 1,500 feet, and at this height, with the help of a glass, I could distinctly see the seven bends of the river Seine. On returning to the earth, I received the compliments of the Commission.

"Arrived at Maubeuge, my first care was to find a suitable spot to erect my furnace, and to make every preparation for the arrival of my balloon from Meudon. Each day my observations contained something new either in the works which the Austrians had thrown up during the night, or in the arrangement of their forces. On the fifth day a piece of cannon had been brought to bear upon the balloon, and shots were fired at me as soon as I appeared above the ramparts. None of the shots took effect, and on the following day the piece was no longer in position. Experience enforced upon me the necessity of forming some provision against these unexpected attacks. I employed the night in fixing cords all round the middle of my balloon. Each of the aerostiers had charge of one of the ropes, and by means of them I could easily move about, and thus get myself out of range of any gun that had been trained to bear against me. I was afterwards ordered to make a reconnaissance at Mayence, and I posted myself between our lines and the enemy at half range of cannon. When the wind, which was tempestuous at first, became calmer, I was able to count the number of cannon on the ramparts, as well as the troops that marched through the streets and in the squares.

"Generally the soldiers of the enemy, all who saw the observer watching them and taking notes, came to the idea that they could do nothing without being seen. Our soldiers were of the same opinion, and consequently they regarded us with great admiration and trust. On the heavy marches they brought us prepared food and wine, which my men

were hardly able to get for themselves, so closely did they require to attend to the ropes. We were encamped upon the banks of the Rhine at Manheim when our general sent me to the opposite bank to parley. As soon as the Austrian officers were made aware that I commanded the balloon, I was overwhelmed with questions and compliments.

"What causes an impression which, till one is accustomed to it, is very alarming, is the noise which the balloon makes when it is struck by successive gales of wind. When the wind has passed, the balloon, which has been pressed into a concave form by the wind, suddenly resumes its globular form with a loud noise heard at a great distance. The silk of the balloon would often burst in a case of this kind, were it not for the restraining power of the network."

After the days of Coutelle we do not read that balloons were made much use of in warfare. The only ascent in the Egypt campaign was that of a tricolor balloon thrown up to commemorate a fete. That Napoleon knew full well the value of the scientific discoveries of his time is clear from the following conversation with a learned Mohammedan, which took place in the great pyramid of Cheops:--

Mussamed. "Noble successor of Alexander, honour to shine invincible arms, and to the unexpected lightning with which your warriors are furnished."

Bonaparte. "Do you believe that that lightning is the work of the children of men? Allah has placed it in our hands by means of the genius of war."

Mussamed. "We recognised by your arms that it is Allah that has sent you--the Delta and all the neighbouring countries are full of thy miracles. But would you be a conqueror if Allah did not permit you?"

Bonaparte. "A celestial body will point by my orders to the dwelling of the clouds, and lightning will descend towards the earth, along a rod of metal from which I can call it forth."

Napoleon did not favour the use of balloons in war. Perhaps it was because he himself had such a splendid genius for war that he depended alone upon himself, and scorned assistance. Perhaps it was because if balloons were discovered to be of real utility, his enemies might make use

of them as well as himself, and France retain no special advantage in them. But however this may be, on his return from Egypt he sold the balloon of Fleurus to Robertson. The company of ballooneers was dissolved, and the balloons themselves disappeared in smoke.

During the war in America, the role which the balloon played was a more important one. The Government of the United States conferred the title of aeronautic engineer upon Mr. Allan, of Rhode Island, who originated the idea of communicating by a telegraphic wire from the balloon to the camp. The first telegraphic message which was transmitted from the aerial regions is that of Professor Love, at Washington, to the President of the United States. The following is this despatch:--

"WASHINGTON, Balloon the 'Enterprise.'

"SIR,--The point of observation commands an extent of nearly fifty miles in diameter. The city, with its girdle of encampments, presents a superb scene. I have great pleasure in sending you this despatch--the first that has been telegraphed from an aerial station--and to know that I should be so much encouraged, from having given the first proof that the aeronautic science can render great assistance in these countries."

In the month of September, 1861, one of the most hardy aeronauts (La Mountain) furnished important information to General M'Clellan. The balloon of La Mountain, which arose from the northern camp upon the Potomac, passed above Washington. La Mountain then cut the cord that connected his balloon with the earth, and rising rapidly to the height of a mile and a half, he found himself directly above his enemies' lines. There he was able to observe perfectly their position and their movements. He then threw over ballast, and ascended to the height of three miles. At this height he encountered a current which carried him in the direction of Maryland, where he descended in safety. General M'Clellan was so much satisfied with the observations taken in the balloon, that, at his request, the order was given to the War Department to construct four new balloons.

If this volume of "The Library of Wonders" had not had for its single object "balloons and their history," we would have devoted a chapter to the numerous attempts made to steer balloons. We shall only say here that aerial navigation should be divided into two kinds with balloons, and

without balloons. In the first case, it is limited to the study of aerial currents, and to the art of rising to those currents which suit the direction of the voyage undertaken. The balloon is not the master of the atmosphere; on the contrary, it is its powerless slave. In the second case, the discovery of Montgolfier is useless; and the question is, to find out a new machine capable of flying in the air, and at the same time heavier than the air. Birds are, without doubt, the best models to study. But with what force shall we replace LIFE? The air-boat of M. Pline seems to us one of the best ideas; but the working of it presents many difficulties. Let us find a motive power at once light and powerful (aluminium and electricity, for example), and we will have definitively conquered the empire of the air.