Meanwhile the possibility of producing a dirigible balloon was again brought into prominence by the suggestion of two aeronauts, Scott and Martainville, to change the shape of the envelope of the balloon. Hitherto, all balloons had been made globular or pear-shaped—shapes that offered great resisting surfaces to the atmosphere. Now it was proposed to make them in the form of long, horizontal cylinders, with pointed ends, these cigar-shaped, or boat-shaped balloons offering much less resistance. But here, as in the case of the flying-machine, engines that were sufficiently strong to work the propellers were found to be too heavy for the balloon to lift. Meanwhile the aeroplane idea was brought into prominence from an unexpected quarter.
Among the numerous observers in the middle of the century who had noted the soaring power of birds, was a French sea-captain named Le Bris. On his long voyages he had studied the movements of the great albatross, which, with wings rigidly distended, outsailed the swiftest ship without any apparent exertion. Anxious to study the wing-mechanism of this bird, the captain, overcoming the scruples of the mariner against killing the sacred sea-rover, shot one of the birds. On removing a wing and spreading it in the wind he thought that it had a very appreciable tendency to pull forward into the breeze, and tended to rise when the wind was strong. Convinced that by duplicating the shape of the bird he could construct a successful flying-machine, Le Bris set to work and succeeded in producing a most remarkable "air-ship."
The body of this machine, which was supposed to correspond to the body of the bird, was made boat-shaped, and was about thirteen feet long and four feet wide, being broadest at its prow, in imitation of the breast of the bird. The front part was decked over, something like the bow of the modern torpedo-boat, and through this deck protruded a small mast which was used for supporting the pulleys and cords used in working the machinery of the wings. Each wing was about twenty-five feet long, so that the entire spread of the machine was fifty feet. There was a tail-like structure so hinged that it could be used for steering up, down, and sidewise, the total area of surface presented to the atmosphere being something over two hundred square feet, although the entire "albatross" weighed something less than a hundred pounds.
The front edges of the wings were made of pieces of wood fashioned like the wings of the albatross, and feathers were imitated by a frame structure covered with canton flannel. The front edges of the wings could be given a rotary motion to fix them at any desired angle by an ingenious device worked by two levers. In operating this artificial bird the captain proposed to stand in the boat and control its flight by these sets of levers and by balancing his body.
Having full confidence in the ability of his invention to soar once it had been given an initial velocity, the captain selected a morning when a good breeze was blowing and hired a cart-driver to carry him out into the neighboring fields. The machine was placed horizontally upon the cart and fastened to it with a rope which could be loosened by the pulling of a slip-knot held by the captain, who took his position in the boat. On reaching the open country the driver put his horse into a brisk trot when, the levers controlling the wings being set, the machine rose gracefully into the air and travelled forward a distance of perhaps a hundred yards. At this moment the running-rope in some unaccountable manner became wound about the body of the driver, hauling him unceremoniously from his seat, and dangling him writhing and shrieking at the end of the rope, several feet above the ground. As it happened, his weight was just sufficient to counterbalance the wind, so that acting in the capacity of the tail of a kite, he assisted materially, if involuntarily, in keeping the artificial bird in flight.
When the captain became aware of what was going on below, he altered the angle of the wings and came slowly to the earth, descending without accident either to himself or to his machine. All things considered, this was a remarkable performance, and it was so considered by people in the neighborhood, who made a hero of the gallant mariner. His next attempt, however, was less successful. Something went wrong with the machine shortly after starting, landing the inventor in a stone-quarry with a broken leg and a shattered machine. This accident also shook the courage of the captain, and for several years he made no more attempts at flight, confining his attention to sailing a coasting-vessel. But his faith in his "albatross" never wavered, even if his courage did for a time, and in 1867 he began building a more elaborate machine, aided by public subscriptions. The outlook for this new device seemed very promising, several fairly successful flights of perhaps two hundred yards having been made, when a sudden gust of wind catching up the machine one day during the momentary absence of the inventor, dashed it to pieces upon the ground. This was the final blow to the hopes of Captain Le Bris, who made no further attempts, his means and his energies being entirely exhausted.
GIFFARD, "THE FULTON OF AERIAL NAVIGATION"
Meanwhile the advocates of the dirigible balloon had not remained idle, many of them attempting to utilize the principle of the aeroplane in connection with a balloon. Some of these machines were of most fantastic design, but one in particular, that of Mr. Henri Giffard, succeeded so well, and proved to be dirigible to such an extent, that Giffard is sometimes referred to by enthusiastic admirers as "the Fulton of aerial navigation." In principle, and indeed in general appearance, this balloon was not unlike some of the balloons built by Santos-Dumont fifty years later. It had the now-familiar cigar shape, common to most modern dirigible balloons; and beneath was suspended a car carrying a steam-engine that worked a screw propeller. The rudder, placed at the stern just below the balloon in a position corresponding to the rudder of a ship, was a large canvas sail set in a frame. The envelope of the balloon was one hundred and fifty feet long and forty feet in diameter and contained about ninety thousand cubic feet of coal-gas. To lessen the danger of igniting this from the engine, Giffard arranged the chimney so that it pointed downward, and suspended it some forty feet below the envelope.
On September 24, 1852, he rose from the Paris Hippodrome, and succeeded in making a headway of from five to seven miles an hour in the face of a strong wind. In response to the rudder his balloon performed some difficult evolutions, turning right or left at the will of the operator. He continued his maneuvers for some time, and then extinguishing his fire, opened the valve and returned safely to the ground. This was a great victory for the advocates of the dirigible balloon, and was indeed a performance that has not until recently been surpassed in the fifty years that have intervened since that time. But despite this initial success, Giffard soon renounced the field of aeronautics, and no worthy successor appeared to take his place for more than a quarter of a century.