Fig. 37.—Forlanini’s Helicopter, 1878.
A still more ambitious helicopter was that shown in Fig. 37 invented by Professor Forlanini, an Italian Civil Engineer, and launched in 1878. The lower screw was fastened to the frame of a steam engine, the upper screw was attached to the crank shaft. Steam was supplied from the globe shown beneath, which was two thirds filled with water, and well heated over a separate fire just before an ascension. As the globe was merely a reservoir of hot water and steam, carrying neither fuel nor furnace, its power waned rapidly. The best flight lasted about twenty seconds, attaining a height of 42 feet. The apparatus weighed 77 pounds, spread 21.5 square feet of screw surface, and lifted about 26.4 pounds per horse power.
Many other helicopter models have been tried from time to time, with various sources of power, without, however, yielding any important results beyond those already given. But these were sufficiently encouraging. If a large machine could be made to lift as many pounds per horse power, it would be easy to build one competent to carry a man. That, indeed, has been done on several occasions. Of the various inventors who have built man-lifting helicopters M. Cornu and M. Bréguet, in France, seem to have been first to attain a measure of success. While their machines have raised a passenger directly from the ground, they have not yet maneuvered in horizontal flight with sufficient speed to be of practical service. However, a few helicoptrists in various countries are still industriously at work, and hope eventually to rival the aëroplanists in the mastery of flight. There will doubtless be room in the sky for both. Perhaps also there will be occupation and a mission for both.
CHAPTER VIII
Having traced the growth of winged models from their earliest beginning to the time when they proved the possibility of mechanical flight, we may now study the evolution of larger machines, designed to carry human beings. Considering first the aëroplane, we may follow the two general methods advocated by various inventors for launching a man safely in the air, both of which led to success. The first of these may be called Henson’s method, the second Lilienthal’s, coupling them with the names of their distinguished pioneer exponents. Henson in 1842 proposed that the pilot should mount a full-power machine, run along a smooth course, and glide into the air without previous experience in the art of navigating. Lilienthal recommended careful preliminary training on a glider, by which the novice should acquire sufficient skill in parrying the wind to qualify him to manage a dynamic machine, under its more complex conditions of control. Others, more cautious still, contended that automatic equilibrium should be secured before a rider risked his bones on the aërial bronco; while still others thought the uncertain beast should be tethered to some point in the sky, say a balloon or taut wire, or the end of a pole; so that however he bucked, or reared, he should not fall over on his rider.
We have noticed in the first chapter some picturesque man-flights, usually deplorable or tragic; and always fruitless for lack of scientific method in experimentation and report to the world. There can be no doubt that such flights were accomplished, mainly, of course, by the aid of gravity; but the difficulty is to ascertain the exact nature of any given performance, the specifications of the apparatus, and the principles of equilibrium and control. Gradually, however, the experimenters improved both in the construction of man-carrying devices and in the manner of imparting their results to their colleagues, or successors; and so the flying enterprise began to assume a progressive aspect, attended with that scientific dignity which invests secure and continuous advance in any branch of knowledge. Little of value, however, can be gleaned from any such flights made prior to the middle of the nineteenth century. From that time forward observers and inventors made definite and fairly methodical efforts to develop the art of gliding and soaring in the air, the first fruit of which was to hasten the advent of the modern aëroplane.
A French novelist and aëronautic writer, G. de la Landelle, relates an amazing adventure in the art of soaring, which may have some foundation in fact, though savoring strongly of fiction. An experienced sailor, Captain Le Bris, having observed the albatross soaring without wing-beat, determined to imitate the fascinating flight of that limber-winged spirit of the sea. To such end he built the bird shown in Fig. 38, a ninety-pound albatross, with arched wings fifty feet across and articulated to the boat-like body. In this the brave aviator would stand upright, turn the wings and tail to maintain his balance, and steer grandly through the sky. Placing this long-winged creature across a cart driven by a peasant, he stood erect and headed against a breeze; the wings set low to prevent lifting till an opportune moment, and the bird held down to the car by a rope which the captain could quickly release. When the horse was a-trot, and the wind blowing freshly, Le Bris raised the front edges of the wings. Thereupon the albatross tugged upward, and the mooring rope was slipped, but accidentally whipped around the driver’s waist. The horse galloped away with the cart; the bird, with the exultant sailor on its back, soared 300 feet into the air, and incidentally carried up the peasant, dangling at the end of the rope and howling with fright. Noting the distress of his passenger, the kindly captain sailed close to earth, so that the peasant might disembark and run to his horse, meaning then to hie away for a long cruise in the clouds. But with this change of weight the vessel seemed not to navigate well; so she was brought skimming to land, with no mishap save a slight damage to the advancing wing, which broke as it touched the ground.
Fig. 38.—Le Bris’ Aëroplane, 1855.