Harper's New Monthly Magazine, Vol. 2, No. 8, January, 1851

by Various

The person who is entitled to the honor of the discovery of the main principle of aeronautics—atmospheric buoyancy—is Roger Bacon, an English monk of the thirteenth century. This eminent man, whose uncommon genius was, in that superstitious and ignorant age, ascribed to his intercourse with the devil, was aware that the air is a material of some consistency, capable, like the ocean, of bearing vessels on its surface; and, in one of his works, he particularly describes the construction of a machine by which he believed it was possible to navigate the air. It is a large, thin, hollow globe of copper, or other suitable metal, which he proposes to fill with "ethereal air or liquid fire," and then to launch from some elevated point into the atmosphere, when he supposes it will float on its surface, like a vessel on the water. He afterward says, "There may be made some flying instrument, so that a man, sitting in the middle of the instrument, and turning some mechanism, may put in motion some artificial wings, which may beat the air like a flying bird." But, though Bacon knew the buoyancy of the atmosphere, he was very imperfectly acquainted with its properties. His idea seems to have been, that the boundaries of the atmosphere are at no great height, and that the aerial vessel, in order to its being borne up, must be placed on the surface of the air, just as a ship, in order to its being supported, must be placed on the surface of the water. And, whatever may be meant by his "ethereal air and liquid fire," there is no evidence that he, or any one living in that age, had any knowledge of the various and distinct gases. Bacon merely reasoned and theorized on the subject; he never attempted to realize these flying projects by actual experiment.

It was not till the year 1782 that the art of aerial navigation was discovered, and the merit of the discovery is due to two brothers, wealthy paper manufacturers, at Annonay, not far from Lyons—Stephen and Joseph Montgolfier. This discovery they did not arrive at from any scientific reasoning founded on the elasticity and weight of the atmosphere, for, though attached to the study of mathematics and chemistry, they do not appear to have particularly turned their attention to aerostatics; but, from observing how clouds and smoke rise and float in the atmosphere, it occurred to Stephen, the younger of the two, that a light paper bag, filled with cloud or smoke, would, from the natural tendency of these substances to ascend, be carried by their force in an upward direction.

About the middle of November, 1782, they made their first experiment in their own chamber at Avignon, with a light paper bag of an oblong shape, which they inflated, by applying burning paper to an orifice in the lower part of the bag, and in a few minutes they had the satisfaction of seeing it ascend to the ceiling of the chamber. Constructing a paper bag of larger dimensions, they made a similar experiment in the open air, with equal success, and, the bag being of a spherical shape, they gave it the name of balloon, from its resemblance to a large, round, short-necked, chemical vessel so called. Finding, from repeated trials, that the larger the balloon the more successful was the experiment, they proceeded to construct one of linen lined with paper, 35 feet in diameter; and, on the 25th of April, 1783, after being filled with rarified air, it rapidly rose to the height of 1000 feet, and fell to the ground at the distance of three-quarters of a mile from the spot where it ascended. Encouraged by this success, the Montgolfiers came to the resolution of making a public experiment with this last constructed balloon at Annonay, on the 5th of June following. It was inflated with heated air, by the lower orifice being placed over a pit or well, in which were burned chopped straw and wool. Two men were sufficient to fill it; but, when fully inflated, eight men were required to prevent it from ascending. On being released from its fastenings, it rose majestically to the height of six or seven thousand feet, and made its descent at the distance of a mile and a half from the point of its departure.

This novel experiment, which forms an important epoch in the history of the art of aeronautics, attracted universal attention, and Stephen Montgolfier, having soon after arrived in Paris, was requested by the Royal Academy of Sciences, whose sittings, immediately on his arrival, he had been invited to attend, to repeat the experiment at their expense. He gladly availed himself of their proposal, and speedily got prepared a large balloon of an elliptical shape, 72 feet high, and 41 feet in diameter. It was finished in a style of great magnificence, and elegantly decorated on the outer surface with beautiful and appropriate designs. When completed, it weighed 1000 pounds. As a preliminary experiment, it raised eight men from the ground, and, on the 12th of September, 1783, it ascended, in the presence of the Royal Academy, with a load of from 400 to 500 pounds; but, in consequence of an injury it received in rising from a violent gust of wind, it did not present the same interesting spectacle as the public experiment previously made, and, upon its descent, it was found to be so seriously damaged, as to be unfit for future experiments. A new one of nearly the same dimensions was, therefore, ordered to be made, to which was added a basket of wicker-work, for the accommodation of a sheep, a cock, and a duck, which were intended as passengers. It was inflated, in the presence of the king and royal family, at Versailles, and, when loosened from its moorings, it rose, with the three animals we have named—the first living creatures who ever ascended in an aerial machine—to the height of about 1500 feet, an accident similar to what befell the other preventing it from attaining a higher elevation. It, however, descended safely with the animals, at the distance of 10,000 feet from the place of its ascent.

Hazardous as it might be, it was now fully demonstrated, that it was quite practicable for man to ascend in the atmosphere, and individuals were soon found sufficiently daring to make the experiment. Another balloon was constructed, 74 feet high, and 48 feet in diameter, and M. Pilatre de Rozier, superintendent of the royal museum, and the Marquis de Arlandes, volunteered to make an aerial voyage. At the bottom, it had an opening of about 15 feet in diameter, around which was a gallery of wicker-work, three feet broad, with a balustrade all around the outer edge, of the same material, three feet high; and, to enable the aeronauts to increase or diminish at pleasure the rarified state of the air within, it was provided with an iron brazier, intended for a fire, which could easily be regulated as necessity required. On the 21st of November, in the same year, the adventurers having taken their places on opposite sides of the gallery, the balloon rose majestically in the sight of an immense multitude of spectators, who witnessed its upward course with mingled sentiments of fear and admiration. The whole machine, with fuel and passengers, weighed 1600 pounds. It rose to the height of at least 3000 feet, and remained in the air from 20 to 25 minutes, visible all the time to the inhabitants of Paris and its environs. At several times it was in imminent danger of taking fire, and the marquis, in terror for his life, would have made a precipitate descent, which, in all probability, would have ended fatally, but M. Pilatre de Rozier, who displayed great coolness and intrepidity, deliberately extinguished the fire with a sponge of water he had provided for the emergency, by which they were enabled to remain in the atmosphere some time longer. They raised and lowered themselves frequently during their excursion, by regulating the fire in the brazier, and finally landed in safety five miles distant from the place where they started, after having sailed over a great portion of Paris. This is the first authentic instance in which man succeeded in putting into practical operation the art of traveling in the air, which had hitherto baffled his ingenuity, though turned to the subject for two thousand years. The news of the novel and adventurous feat rapidly spread over the whole civilized world, and aerial ascents in balloons constructed on the same principle were made in other cities of France, in Italy, and in the United States of America.

The two Montgolfiers soon obtained a high and wide-spread reputation; and the Royal Academy of Arts and Sciences of Paris voted a gold medal to Stephen, the younger brother. It was to heated or rarified air that these balloons owed their ascending power; but the Montgolfiers, in the paper in which they communicated their discovery to the Royal Academy, erroneously attributed the ascending power, not to the rarified air in the balloon, but to a peculiar gas they supposed to be evolved by the combustion of chopped straw and wool mixed together, to which the name of Montgolfiers' gas was given, it being believed for a time, even by the members of the Academy, that a new kind of gas, different from hydrogen, and lighter than common air, had been discovered.

Hydrogen gas, or, as it was also called, inflammable air, whose specific gravity was first discovered in 1766, by Henry Cavendish, though the gas itself had been known long before to coal-miners, from its fatal effects, was, from its being the lightest gas known, early taken advantage of for inflating balloons. It indeed occurred to the ingenious Dr. Black of Edinburgh, as soon as he read Mr. Cavendish's paper, which appeared in the Philosophical Transactions for 1766, that if a sufficiently thin and light bladder were filled with this gas, the bladder would necessarily ascend in the atmosphere, as it would form a mass lighter than the same bulk of atmospheric air. Not long after, it suggested itself to Tiberius Cavallo, an Italian philosopher, when he first began to study the subject of air, that it was possible to construct a vessel which, when filled with hydrogen gas, would ascend in the atmosphere. In 1782, he actually attempted to perform the experiment, though the only success he had was to let soap balls, filled with that gas, ascend by themselves rapidly in the air, which, says he, were perhaps the first sort of inflammable air balloons ever made; and he read an account of his experiments to the Royal Society at their public meeting on June 20, 1782. But, during the later part of the year 1783, two gentlemen in the city of Philadelphia actually tested the value of hydrogen gas as a means of inflating balloons. The French Academy, guided by the suggestion of Dr. Black, and the experiments of Cavallo, also concluded to make the experiment of raising a balloon inflated with the same gas. To defray the expense of the undertaking, a subscription was opened, and so great was the enthusiasm excited by the design among people of all ranks and classes, that the requisite sum was speedily subscribed for. A silken bag from lute-string silk, about thirteen feet in diameter, and of a globular shape, was constructed by the Messrs. Roberts, under the superintendence of M. Charles, professor of experimental philosophy; and, to render the bag impervious to the gas—a very essential object in balloon manufacture—it was covered with a varnish composed of gum elastic dissolved in spirits of turpentine. It had but one aperture, like the neck of a bottle, into which was fastened the stop-cock for the convenience of introducing and stopping-off the gas. It was constructed and inflated near the Place of Victories, in August, 1783, and after being inflated, which was then no easy task, occupying several days, it was removed on the morning of the 27th of that month, before daylight, to the Camp of Mars (two miles distant), the place appointed for its ascent. About five o'clock in the afternoon, it was released from its fastenings, and rose, in the presence of some hundred thousands of applauding spectators, to a height upward of 3000 feet; and, after remaining in the atmosphere for three-quarters of an hour, descended in a field near Gonesse, a village about fifteen miles distant from the Camp of Mars. This marks another important era in the history of aeronautics. The hydrogen-gas balloon, in the first place, is attended with less risk than the Montgolfiers' balloon, which requires the dangerous presence of a fire to preserve the air in a sufficiently rarified state; and, in the second place, it has a much greater ascending power than rarified air balloons of the same size, in consequence of its superior lightness.

M. Charles and the two Messrs. Roberts now resolved to undertake an aerial excursion in a balloon of this description. With this view, the Messrs. Roberts formed one of silk, varnished with gum elastic, of a spherical shape, 27 feet in diameter, with a car suspended from it by several cords, which were fastened to a net drawn over the upper part of the balloon. To prevent the danger which might arise from the expansion of the gas under a diminished pressure of the atmosphere in the higher regions, the balloon was furnished with a valve, to permit the free discharge of gas, as occasion might require. The hydrogen gas with which it was filled was 5¼ lighter than common air, and the filling lasted several days. On December 17, 1783, M. Charles and one of the Roberts made their ascent from the garden of the Tuilleries, and rose to the height of 6000 feet. After a voyage of an hour and three-quarters, they descended at Nesle, a distance of 27 miles from the place of their departure. On their descent, M. Roberts having left the car, which lightened the vessel about 130 pounds, M. Charles reascended, and in twenty minutes mounted with great rapidity to the height of 9000 feet. When he left the earth, the thermometer stood at 47 degrees, but, in the space of ten minutes, it fell 21 degrees. On making this great and sudden transition into an atmosphere so intensely cold, he felt as if his blood had been freezing, and experienced a severe pain in the right ear and jaw. He passed through different currents of air, and, in the higher regions, the expansion of the gas was so great, that the balloon must have burst, had he not speedily opened the valve, and allowed part of the gas to escape. After having risen to the height of 10,500 feet, he descended, about three miles from the place where M. Roberts stepped out of the car.

Jean Pierre Blanchard, a Frenchman, who had long exerted his ingenuity, but with little success, in attempting to perfect a mechanical contrivance by which he might be enabled to fly, was the next to prepare a balloon upon the hydrogen-gas principle. It was 27 feet in diameter. He ascended from Paris, March 2d, 1784, accompanied by a Benedictine friar. After rising to the height of 15 feet, the balloon was precipitated to the ground with a violent shock, which so frightened the friar, that he would not again leave terra firma. M. Blanchard re-ascended alone, and, in his ascent, he passed through various currents of air, as aeronauts generally do. He rose to the height of 9600 feet, where he suffered from extreme cold, and was oppressed with drowsiness. As a means of directing his course, he had attached to the car an apparatus consisting of a rudder and two wings, but found that they had little or no controlling power over the balloon. He continued his voyage for an hour and a quarter, when he descended in safety.

During the course of the year subsequent to the Montgolfiers' discovery, several experiments on the ascending power of balloons had been made in England; but the first person who there ventured on an aerial voyage was Vincent Lunardi, an Italian, who ascended from London, September 21, 1784. In the succeeding year, he gratified the inhabitants of Glasgow and Edinburgh with the spectacle of an aerial excursion, which they had never witnessed before.