Early balloon voyages. The spherical balloon. The parachute
Man has had, from very early times, a wish to ﬂy. In the Book of Psalms (PS. lv. 6) David says, “And I said, Oh that I had wings like a dove! for then would I ﬂy away, and be at rest.”
In Roman mythology, we ﬁnd the story of Daedalus, who procured wings for himself and his son Icarus, and fastened them on with wax. With these he ﬂew safely over the [Egean Sea, but as Icarus ﬂew too near the sun, the wax, by which his wings were fastened, melted in the sun’s heat, and he fell into the sea and was drowned. Archytas, of Tarentum, it is said, ﬂew a kite (400 BC), and even made a wooden pigeon which rose in the air for a few minutes. Simon, the magician, attempted, in Rome, to ﬂy from one house to another in 66 A.D. About the end of the ﬁfteenth century, I; B. Dante, a mathematician of Pérouse, rose above the Lake Trasimene, with artiﬁcial wings attached to his body, but one day he fell on the church of N otre Dame and broke his leg. An English Benedictine Monk, Olivier de Malmsbury, provided himself with wings, but he also came to grief and broke his legs. In Scotland, in I 508, the Abbot Damian proclaimed to King James IV. that he would attempt to ﬂy from Stirling Castle to France. He provided himself, it is said, with artiﬁcial wings made out of birds’ feathers, and launched forth into the air; he fell and broke his legs, but said if he had used eagles’ feathers, he would have succeeded. In 1678, Besmier made a pair of wings, with large and curved blades, which had arm and leg attachments, and by twisting both his arms and legs about, he was said to have ﬂown a short distance with his machine. In 1775 a certain M. de la Folie, of Rouen, tried to make a ﬂying machine by combining certain kinds of electrical apparatus. At Paris, the Marquis de Bacqueville , attempted to ﬂy from his house on the river and fell in the attempt. Blanchard, the ﬁrst voyager by profession, also tried a ﬂying machine, and fared no better.
It is only within very recent years, owing to the development of the petrol engine, that anything has been constructed in the nature of an airship capable of travelling long distances, when driven by engines and having its direction controlled by a rudder. This remark also applies to heavier than air ﬂying machines. Hitherto, the aeronaut could only make an ascent in a (spherical) drifting balloon, ﬁlled with hydrogen or coal gas, incapable of control and with no motive power to propel it, being drifted about with the wind, so that he could not tell where he would land, on a descent being made.
- Machines for navigating the air are divided into different
- Machines lighter than air, whose lifting force is obtained from the hydrostatic pressure of the atmosphere. Example—(a) drifting balloons; (b) dirigible balloons or airships.
- Machines heavier than air, whose lifting force is obtained from the reaction of the wind, or from mechanical energy, or from both——(a) the kite; (b) the helicopter; (a) the glider,- (d) the aeroplane or ﬂying machine.
In 1670, Lana, the Jesuit Father, suggested the construction of a balloon, with four hollow copper globes (each 25 feet diameter, and 5%, of an inch in thickness), and said, if they were exhausted of air the balloon would ascend, being then lighter than air. It was to carry a sail and a basket large enough for one man (Fig. I).
In 1783, the brothers Montgolﬁer, at Annonay, near Lyon, in France, after experimenting, ﬁtted a structure, formed of light material, with heated air (which became rareﬁed and light) and the balloon ascended to the roof of the apartment where they were. After that they carried out further experiments in the open, and, on June 5, 1783, they gave a public demonstration of their experiments with a ﬁre balloon. A linen globe, 105 feet in circumference, was inﬂated with hot air over a ﬁre, and when released, the balloon rose to a height of 6000 feet and descended in re minutes at a distance of IF; miles.
Later on a balloon was made in Paris by two brothers, called Robert. They adopted the scientiﬁc principle on which the discovery of the balloon was brought about, and which had been announced in Edinburgh, in 1767, by Dr. Black, Professor of Chemistry, viz. that a vessel ﬁlled with hydrogen gas would naturally rise in the air. They ﬁlled their 13 feet diameter balloon with hydrogen, and on August 27 the balloon ascended from the Champ de Mars, Paris, and rose to a height of over 3000 feet, and in about one hour it fell in a ﬁeld near to Gonesse. On September 19, 178;, Joseph Montgolﬁer, at Versailles, sent up a balloon which rose to a height of 1500 feet, and it carried a sheep, a cock and a duck as the ﬁrst aerial travellers ; all descended safely.
M. Francois Pilatre de Rozier, a young naturalist (who later on was killed in attempting to cross the English Channel in a balloon) was the ﬁrst person to ascend in a balloon. He ﬁrst went up in a captive balloon, after that in a free balloon (both were ﬁre balloons), which rose to a height of 500 feet over Paris, on November 2r, 1783, and had a safe descent. On December I, Charles ascended in a balloon, inﬂated with hydrogen, to a height of 9000 feet. In 1784, Vincent Lunardi, an Italian, ascended from London in a balloon ﬁlled with hydrogen, in the presence of, it was said, 150,000 people, and descended safely in the parish of Standon, near Ware, where a stone, surrounded by a railing and bearing an inscription of the event, was erected on the spot where he descended.
These experiments were often repeated afterwards. In 1785, Blanchard and Dr. Jeffries ﬁrst crossed the Channel from Dover to Calais in a balloon.
General Musnier made a dirigible balloon with three hand-driven propellers to guide it; he was the ﬁrst to use air bags inside the gas envelope, and rigidly connected the car to the body. We may regard him as the forerunner of the modern inventor. He died in 1793.
In 1804, Robertson ascended from St. Petersburg. In I812, Sadler ascended at Dublin to cross the Channel to Liverpool, but he came to grief on the way, falling into the sea and being drowned.
Green, the famous aeronaut, ﬁrst ascended on July 19, 1821. He substituted coal gas for hydrogen. In 1836, he and two others ascended from Vauxhall Gardens, London, to an elevation of 1200 feet, and, after an adventuresome voyage, the balloon descended in the duchy of Nassau, near to Weilburg. The journey of 500 miles lasted 18 hours and ended safely.
Wise, in America, made there the ﬁrst ascent in a balloon inﬂated with hydrogen gas on May 2, 1835. He was the pioneer in aeronautics on- the other side of the Atlantic. On April I 5, I87 5, Sivel, Crocé, Spincelli, and Tissandier reached a height of 27,950 feet. All were asphyxiated except Tissandier. Many experiments with balloons have been made since those days, but the inability to guide them, the want of motive power to propel them, and their utter helplessness in air currents, which drift them along in any direction, have caused experimenters to abandon them for the dirigible balloon or airship, which will be described later on.
A drifting balloon (Fig. 2) is of a spherical shape, except the neck or tail which slopes downwards. The whole somewhat resembles a pear. The envelope is made in pieces, each piece being called a “gore.” The “gores " consist of gold-beaters’ skin, silk, linen, or cambric, sewn or cemented together and covered with linseed oil, and varnished to render them gas tight, as far as possible. A small part of each is cut away at the top, leaving an aperture, the edges of which are enclosed by a wooden hoop, from I foot to 3 feet in diameter, according to the size of the balloon. The gas valve is attached to this hoop, and is composed of two semicircular shutters hinged to the frame and closed by a spring; the valve is opened by a cord, the “ valve line,” which passes through the balloon and comes out at the opening in the tail. A closely meshed network is ﬁxed to the hoop and envelops the whole of the upper part of the balloon, and supports the ring from which the car is suspended by strong ropes, from 4 feet to 5 feet long. The car is a wicker basket, suspended between 7 and 8 feet below the neck, so that the aeronaut can reach the latter by mounting the ring. To save expense sometimes cotton or alpaca is used for the envelope, and, of course, this is also varnished. The anchor is a 5-pronged fork attached by a rope, say 100 feet long.
The ballast consists of sand in bags, each holding about half a cwt. The less weight carried the better, so cane ropes, and steel wire are used in the construction of balloons. Coal gas is now used for inﬂating purposes. When the balloon has made an ascent and the aeronaut wishes to ascend higher, he throws out some of the ballast, thus increasing the buoyancy. If he wishes to descend, he opens the gas valve and lets some of the gas escape. By allowing gas to escape on the one hand, and throwing out ballast 0n the other, the aeronaut has the power of making the balloon remain at diﬂerent heights in the atmosphere, but as there is no propelling force the balloon is at the entire mercy of all the air currents encountered, and so drifts about helplessly according to the direction of the wind. With the continual release of gas from the balloon there must arise a diminution of buoyancy or lifting power, and when all the sand has been thrown out and the balloon has descended to earth, it cannot be made to ascend again until the envelope is reﬁlled with gas.
The higher a balloon ascends the less is the atmospheric pressure encountered. It is well known that the density or pressure of the atmosphere gets less the higher we go above sea level, and so the gas in the envelope expands, for as the outside pressure diminishes so the inside pressure increases, and unless a compensating device were adopted, the envelop would burst from the expansion of the contained gas, and the aeronaut would be dashed to pieces. The gas in the balloon also tends to expand when heated by the sun’s rays, and to contract when the atmosphere is cold.
In the early days a balloon was never ﬁlled completely with gas, and its lower part or tail was left constantly open, so that as it expanded on rising, the dilated gas would ﬁnd an exit from this opening. It is still the practice to keep the mouth open, or slightly so. In modern balloons the envelope is kept at the same state of tension, in spite of the expansion and contraction of the contained gas, by a diﬁ'erent method; this consists of a small balloon, or air bag, put inside the main balloon. This miniature balloon is kept full of air, pumped into it by a pump driven by the engines, there being valves to prevent over distension.
If the gas in the main balloon expands it presSes against the small balloon, and drives out the air through an exhaust valve, and so causes this to collapse more or less, thus increasing the space in the main envelope for the expanding gas, and this prevents undue stretching of the silk covering. Should the gas contract, then the pump forces more air into the supplementary balloon, which expands, and so increases the pressure of the gas in the main envelope. Advantage is also taken of this method to allow an airship to ascend higher without losing gas, and descend withoutk relying entirely on the throwing out of ballast.
Mr. Green, the aeronaut, used a method by which he was able to keep the balloon at a moderate altitude while still retaining the reserve of lifting power; he used what is known as a guide rope. From the car of the balloon was suspended a long heavy rope which hung vertically downwards so as to touch the ground; this, Of course, gave extra weight to the balloon when the end of the rope was clear of the ground, and acted against the buoyancy of the balloon to prevent it from rising higher.
Should the buoyancy decrease the end of the rope will trail on the ground, and as the balloon descends, more and more of the rope will trail on the ground, thus relieving the balloon of some of the weight of the rope, and so the buoyancy will increase, the descent will be checked, and the balloon will again ascend; thus, the rope acts as an automatic regulator of the balloon’s height in the atmosphere .
Ilgﬂatialzaf a balloon wit/I grim—W hen hydrogen gas is used the balloon is generally inﬂated through a pipe coming direct from the gas producer, but to charge a balloon with pure hydrogen gas is a slow and uncertain, as well as a laborious undertaking (extending sometimes over two or three days); it takes many carboys of sulphuric or hydrochloric acid, and many hundred-weights of iron to produce a sufﬁcient volume of hydrogen gas. A series of connected vats or barrels must be ﬁlled with acid diluted with water, and the gas must be washed and cooled by water and dried by being passed over quicklime before it is taken to the balloon.
Carburetted hydrogen or coal gas is a much better and cheaper gas to use for inﬂating balloons; they are generally ﬁlled at the gasworks direct through a pipe leading from the gasometer.
Sometimes instead of the above methods, compressed gas cylinders are used, pipes conveying the gas from the cylinders to the balloon.
A parachute (Fig. 3) is an apparatus attached to a balloon, and is used for conveying the aeronaut to earth in safety should an accident to the balloon occur. Sebastian Lenormond descended from a tree in a parachute in 1783. Blanchard, at Strassburg, made a descent from a balloon in 1787, and Garnarin did the same in 1797, falling through‘ a space of 3000 feet to the ground. A parachute is shaped like an umbrella, having the outer extremities of the rods, which carry the canvas, ﬁrmly joined by ropes or stays to the lower part of the central stalk. This last consists of a hollow iron tube through which a rope passes, and which connects the balloon above with the car containing the aeronaut. The rope is so fastened, that when the balloon is cut loose, the parachute and car are still connected.
While ascending it remains closed like an umbrella; it can be detached from the balloon by cutting the rope which fastens it. On being set free the resistance of the air immediately causes it to expand, retarding the velocity of descent, and the parachute, with the aeronaut, comes safely to earth. In 1802, M. Garverin descended, in London, in a parachute 2 3 feet in diamete ; and at a height of 8000 feet he cut the rope which attached him to the balloon. The descent was made in safety. In 1837, Mr. Cocking descended , near London, from a parachute suspended from Mr. Green’s “Nassau” balloon. It was liberated at a height of 5000 feet. The apparatus descended at ﬁrst apparently all right, then it suddenly collapsed and descended very rapidly, and the aeronaut was found dashed to pieces. , Professor Baldwin descended from a parachute several times, in I888, at the Alexandra Palace, London. We saw a balloon ascent and a parachute descent, made from Queen’s Park, Glasgow, in 1893.