The news of this extraordinary experiment soon reached Paris. where it produced a great sensation. A commission was appointed by the Academy of Sciences to report upon it. Public curio..ity, however, could not await the tardy decision of this body, and accordingly a subscription was raised to defray the expense of repeating the Annonay experiment. Such was the excitement that the subscription was filled in a few days, and the construction of the balloon was intrusted to the brothers Robert, famous philosophical instrument makers of the day, and to Professor Charles, a young but experienced physicist. As the detailed account of the Annonay ascent had not reached Paris, and a. nothing was therefore known of the Mont golfier gas, Charles fixed upon hydrogen as the gas most likely to insure slimes, It how ever, a formidable undertaking to produce it in sufficient abundance for a balloon, as it was at that time only prepared in small quantities in the lecture room and laboratory. By ingenuity and perseverance combined Ice triumphed over this difficulty, and succeeded in filling, in the course of four days, a silk globe 12 feet in diameter. This balloon was transferred to the Champs de Mars, the largest open space in Paris, where, on August 27, 17S3, it ascended in the presence of 300,000 spectators, half the popula tion of the city. At the instance of the commis sion already referred to, Etienne Montgolfier constructed a fire-balloon 72 feet high and 41 feet in diameter. It ascended before the commis sion on September 12, 1783, but being held cap tive it was much injured by a violent wind which blew at the time, and after it descended it was finally broken up by heavy rains. Another was made, of nearly the same dimensions, which as cended on the nineteenth of the same month at Versailles. the king and royal fancily witnessing the spectacle. This ascent is worthy of note, from the fact that a sheep, a cock, and a duck were placed in an osier basket attached to the lower part of the balloon, and that these first aerial voyagers reached the ground again in fety.
The balloon was now an accomplished fact, and it began to be discussed whether it might not be serviceable as an airship for bearing men aloft as passengers. The solution of this ques tion was first given by PiRare de foxier. In a montgolfiere, as the heated air-balloon was called, 74 feet high and 48 feet in diameter, sup porting at its base a gallery of wicker-wo•k, he, in company with the Alarquis d'Arlandes, made the first aerial voyage, November 21, 1783. They remained in the air twenty-five minutes, and sailed across the Seine and over a consider able part of Paris. The year 1783, so fertile in the annals of aeronautics, witnessed an addi tional, end even more satisfactory, triumph. On December 1, Professor Charles, along with Robert, rose from the Tuileries gardens along a hydrogen balloon—then called a Charliere made with the proceeds of a public subscription. This balloon was made of alternately red and yellow gores of silk sewed together and coated with caoutchoue varnish. It was covered with a net which supported the car, and was furnished with a valve, a barometer, and sand-ballast, and was, in fact, a complete aerial machine. In eon sequence of the danger attending the use of tire balloons. and the engrossing. attention \\•h they demand of the aeronaut, they have now en tirely given way to the hydrogen or coal-gas bal loon-3 for long voyages. Before they became obsolete several remarkable voyages were made in them. The same Pil5t•e de Rozier made 30 leagues in one of them, the longest voyage ever executed in a montgolfiere. Among the names of the first. professional aeronauts, those of Lunardi, Blanchard, and Garnerin deserve spe cial note. Lunardi was the first who made an ascent in Great Britain; and Blanchard, along with an American, Dr. .lefTries, the Eng lish Channel from Dover to Calais: in eirenne stances of almost unparalleled clanger. .Tanuary 7, 1785. Garnerin first descended from a balloon by a parachute (q.v.), October 22, 1797. It is
much to be regretted that the first aeronaut, Pilatre de Rozier, fell a victim to a blind de votion to his art. In order to outvie Blanchard, lie constructed a compound machine, consisting of a hydrogen balloon above and a montgolfiere below, and started from Boulogne, accompanied by a physicist named Ronmin, on the morning of June 5, 1785. lIe had not ascended many minutes when, as it afterward appeared, on attempting to open the valve of the hydrogen balloon by the rope attached to it, he caused a rent of several yards in it, so that it emptied itself almost immediately, and fell on the mont golfiere beneath. The fire in the latter not being kindled, the whole machine fell with a frightful rapidity to the earth, and the ill-fated aeronauts perished on the spot whence they had arisen.
As stated above, the second balloon built by Professor Charles embodied all the essentials of the ordinary balloon of the present day. Briefly described, the balloon, as it is commonly employed, is a large pear-shaped bag, made of any pliable cloth, usually alpaca or cotton (though silk is the best), eovered with a varnish, made by dissolving caoutchoue in oil of turpen tine, to render it air-tight. The common size of this bag varies from 20 to 30 feet in equatorial diameter, with a proportionate height. The month or neck of this bag is just large enough to enable a man to get inside to make any 110MS sary repairs. and is, of course, turned downward when the balloon is inflated. A network of hempen or cotton twine is accurately fitted to the balloon, and the ends of the separate cords, of which it is formed, are tied to a circular hoop placed a few feet below the neck. The car, gen erally a large wicker-basket, is suspended by ropes from this hoop and hangs at a consider able distance below, so that the aeronaut may Ice removed from the vicinity of the gas. The net-work serves to distribute the weight of the car and its charge equally over the whole upper surface of the balloon. One of the most impor tant requisites in the construction is the valve, which is introduced into the top of the balloon. It consists of a wooden or metal clapper, from one foot to three feet in diameter, opening in ward, and kept closed by springs. A rope at tached to this valve descends through the neck into the car, where, to prevent accidental open ing:, it is allowed to dangle freely. The equip ment. of the car comprises the ballast, or sand bags, by emptying which the balloon may be light ened; the barometer, or corresponding apparatus for telling the height ascended, or the upward or downward course of the balloon; the map and compass, for showing the direction of the voyage; and the grappling-iron, tied to the end of a long rope, for anchoring the balloon at the descent. During his flight the aeronaut has at his dis posal the means of guiding his airship only in an upward or downward direction, the motion of translation being wholly dependent on the wind by which it is borne. if he wishes to ascend, he throws some of the ballast over the side of the car, and if to descend, he pulls the valve-rope, so that, the gas rushing by virtue of its specific lightness through the passage made for it by the open valve, the buoyant material may be lessened. It is evident that the power of thus directing his machine becomes more limited after each discharge of ballast or gas, for, in each case, there is an unrepaired loss of the means neces sary to it. In ordinary flights the mouth of the balloon is left open, so that there is no danger of explosion arising from the expansion of the gas in the rarer regions of the atmosphere. The gas most commonly used for balloons is coal gas. The diffusion that takes place through the open neck is inconsiderable during the few hours that an aerial voyage lasts. Early aeronauts. who kept their balloons closed, frequently ran con siderable risk by inattention to the valve when the imprisoned gas demanded vent for its ex pansion.