Aeronautics (Gr.Aeronautics 10094 air, andAeronautics 10095 of or belonging to ships), or Aerostation (Gr.Aeronautics 10096 andAeronautics 10097 standing), the art of sailing in and navigating the air, and of raising and sustaining substances by means of gases specifically lighter than the atmosphere, contained in a spheroidal bag called a balloon. The former term is the more comprehensive of the two, and includes the whole secience of aerial navigation, while the latter is generally confined to ballooning. The myths of DAedalus and Icarus show that the attempts of man to soar above the earth commenced in prehistoric times. Flying machines were expected to effect this object. Archytas of Tarentum is said to have manufactured, 400 years B. C, a wooden pigeon which sustained itself in the air a few minutes. Simon Magus, according to Suetonius, met his death in Rome in the reign of the emperor Nero in an attempt to fly from one house to another. Roger Bacon had some notion of a flying machine to be propelled by a system of wings; and in the latter part of the 15th century Dante, a mathematician of Perugia, rose above Lake Thrasimene by means of artificial wings attached to his body.

Many similar attempts have been made since then by persons imperfectly acquainted with the principles of mechanical philosophy, which have invariably resulted in failure, and the problem is as far from solution as ever. The discovery of the properties of hydrogen gas by Cavendish in 1766 gave the first hint of a practical method of aerial navigation. This is the lightest of the gases, being a little more than 14 times rarer than atmospheric air; and as early as 1767 Professor Black of Edinburgh announced to his class that a vessel filled with it would naturally rise into the air. A few years later (178*2) Cavallo made a series of experiments on the subject, but did not succeed in raising anything heavier than a soap bubble. The honor of preparing and sending up the first balloon belongs to the brothers Stephen and Joseph Montgolfier, paper manufacturers at Annonay, near Lyons, who, however, at the outset of their experiments, knew nothing of hydrogen gas, and employed heated air to inflate their machine, without apparently being aware of its superior buoyancy to the atmosphere. Their balloon was constructed of linen cloth lined with paper, under which a lire was kindled, fed with bundles of chopped straw.

By this means dense volumes of smoke were produced, which filled the balloon; and it would seem that they actually expected the latter to be raised by the ascending power of the smoke, instead of its true cause, the rarefaction of the heated air.

First Balloons made by Montgolfier.

First Balloons made by Montgolfier.

On June 5, 1783, their balloon, weighing 500 pounds, first rose into the atmosphere. It reached an altitude of nearly a mile, remained suspended a few minutes, and, as the air escaped, gradually returned to the earth. The event singularly impressed all classes of society, and the most extravagant notions were entertained of the uses to which balloons might be applied. Several successful ascents were made within the next few months from Paris, and on Nov. 21, 1783, Pilatre de Rozier and the marquis d'Arlandes, the first adventurers who durst ascend in an unconfined balloon, astonished the world by rising to the height of 3,000 feet, descending in safety not far from Paris. These experiments were mostly made with the Montgolfier balloon, or mont-golfiere, which was inflated with heated air, and the early aeronauts were obliged to carry with them a supply of fuel to renew the rarefied air as fast as it escaped. This clumsy and dangerous expedient subsequently led to disastrous results. On Dec. 1 of the same year Messrs. Charles and Robert left Paris in a hydrogen balloon, in the presence of 600,000 spectators, and after a trip of two hours descended in safety near Nesle, 25 m. distant.

M. Charles immediately reascended alone, and had the satisfaction of seeing the sun, which had set when he left the earth, rise and set again. He descended in safety in 35 minutes, 9 m. from his starting point. In this expedition the fall of the barometer and thermometer was first noticed. The first, sinking to 20.05 inches, indicated an ascent of about 9,700 feet. The thermometer sank to 21° F. In 1784 upward of 52 balloon ascents are recorded, the most remarkable being those of Messrs. Charles and Robert, who reached an altitude of 13,000 feet; of Blanchard, the first aerial voyager by profession; and of Prince Charles de Lignes. In January, 1785, Blanchard and Dr. John Jeffries, of Boston, accomplished the daring feat of crossing the channel from Dover to France, narrowly escaping being wrecked in the sea. In the same year occurred the first fatal accident connected with ballooning. Pilatre de Rozier attempted, with a young man named Ro-maine Laine, to cross from France to England in a hydrogen balloon, under which was suspended a small montgolfiere for the purpose of increasing or diminishing the ascensional power at pleasure.

The hydrogen, by its expansion in the rarer upper strata of the atmosphere, pressed down through the tubular neck of the balloon, and reaching the fire of the montgolfiere was at once ignited. Both balloons were quickly consumed, and the voyagers were precipitated from a height of 3,000 feet upon the rocks near the French coast. As this calamitous occurrence was occasioned by the neglect of proper precautions, aeronauts were not deterred by it. Ascents to the number of many thousands have since been made in Europe and America, both in montgolfieres and gas balloons, and it is believed that not more than 25 persons have lost their lives in consequence. Of this number of ascents, however, few only have been undertaken for scientific purposes, most having been made merely as a popular spectacle or for the sake of amusement. In this regard both hemispheres have furnished skilful and daring aeronauts. Among the earlier French voyagers was Blanchard, who died in 1809, having made more than 66 ascents, one of which took place in New York in 1796. Mme. Blanchard sometimes accompanied him, and after his death she occasionally ascended alone.