Having repaired the great bird’s wing, Captain Le Bris next made a launching from the arm of a derrick, 30 feet above the ground, overlooking a quarry 70 feet deep. The attendant swains stood open-mouthed, wondering whether this madman would overleap the clouds, or promptly butt out his brains on a jagged rock. When the wind blowing from the quarry seemed to float him in perfect poise, he tripped the suspension hook, and headed for the precipice on even keel. He was now happily launched, and keen for an aërial journey; but after passing the brink, he seemed to encounter an eddy which tilted his craft forward. The vessel dipped and rose; the captain plied his levers, turning now the tail, now the pinions. He crossed safely over the invisible breakers, and reached the quiet air of the quarry on level wing. But now his forward speed was lost, the great bird sank rapidly and crashed upon the rocky bed below. The wary seaman anticipating a bump, sprang upward to soften his fall; but a lever rebounding from the shock, hit one of his legs and broke it.
Some twelve or thirteen years later, in 1867, Le Bris, aided by a public subscription at Brest, built a second albatross, with which he made a number of small flights, sometimes riding it himself, and sometimes replacing his weight by ballast. On one occasion the loaded bird, held by a light line, rose 150 feet and advanced against the wind. Suddenly the sailors holding the line observed it slacken, and saw with amazement the long-winged creature soar forward 600 feet, as stately and serene as its living prototype. Presently encountering a sheltered and quiet region of air before some rising ground, it settled softly to earth in perfect equipoise. But on a subsequent launching from the same favorable ground, the dumb creature pitched forward and plunged to the earth where it lay shattered and torn in a hopeless tangle. Le Bris looked on the wreck in despair, surveying sadly the remains of his once cherished bird; then sat upon the débris a long time, his head between his hands, his heart broken, his mind tortured with anguish. Impoverished, chagrined, derided, he now must abandon the albatross business. Five years later this intrepid sailor of sea and air was killed by some ruffians, in 1872, while a constable in his native place, and after a period of honorable service to the state in the Franco-Prussian War.
The story is more romantic than instructive, for want of exact data. To give the experiments their proper value to others, fuller details of the mechanism should be furnished, and adequate measurements of the speed and direction of the aërial currents. At one time the sailing was even, at another, rough, though outwardly the conditions appeared the same. Apparently the successful flights occurred when the bird was launched to windward from rising ground, that is, when the current had an upward slant, to exert a propulsive effort. This species of soaring has been observed frequently in nature, and has been imitated both with models and with man-carrying gliders. Nevertheless Le Bris’ experiments were very remarkable for the time, and, if adequately reported, might have proved to be of much interest and value to aëronautical science.
Another Frenchman alert to the glory of aërial motion was L. P. Mouillard, the poet-farmer of Algeria. From boyhood he studied the birds with unabated interest and pleasure. He would journey miles to attend the “morning prayer” of the starlings in the forest of Baba-Ali; noting, just before sunrise, how their melodies suddenly hushed, and the forest seemed to bound upward, and heaven filled with the music of innumerable wings. He would time the shadow of the high bird of passage riding the hurricane from continent to continent. He saw the tyrant eagle fold his wings in mid air and plunge a thousand feet in ferocious swoop after the swift-fleeing duck or rabbit. He loved to watch the great tawny vulture on the mountain top shake the dew from his vast plumes, straddle the morning wind, and all day long, with never a beat of those grand pinions, soar godlike through immensity, the marvel and delight of the nether world. When the electric wind of the desert, blowing from Central Africa, brought the big scavengers and noble birds of prey, he sat on the ground scrutinizing their majestic flight and planning to imitate it. He would lie in ambush where the silent-rowing owl darted at dusk through the timber, fierce and swift as the eagle; a dreadful thing, with its night piercing eyes, its big ears and beak, its horrid talons, its sudden shriek startling the forest with ominous echoes. No feature escaped him, and least of all an aërodynamic one.
For thirty years he continued these studies. He would bring home the birds, lay them on their backs and mark their contour on paper, measure their projected area, weigh and compare them. He formulated curious conclusions about sailors and rowers, the functions of tail and quill feathers, weight and wing-spread, bulk, agglomeration of mass, resistance and velocity. He notes that only massive birds soar well, the broad-winged ones requiring a moderate wind, the narrow-winged ones requiring a gale, and sailing with perfect ease in a tempest; and he concludes that man may imitate both types. His book[24] is replete with charming anecdotes, observations and quaint theories, interesting alike to ornithology and aviation.
But Mouillard did more than theorize; he built soaring machines and soared a little. His third and best glider, illustrated in Fig. 39, was a tailless monoplane made of curved agave sticks screwed to boards, and covered with muslin. The aviator, standing in the open space C, harnessed the plane on with straps looped round his legs and shoulders, and fastened to the points D D. His forearms, passing under straps, rested on the board, enabling him to tilt the whole by shifting his weight. In order to vary the dihedral angle between the wings, they were hinged together and actuated by rods running from the man’s feet to the ends of the boards, hardly as far out as the center of wind pressure, thus apparently stressing his legs like a wishbone.
Fig. 39.—Mouillard’s Aëroplane.
He now sent the home folks away from the farm, buckled on his wings and walked along the prairie road waiting for a breeze. The road was raised five feet above the plain and bordered by ditches ten feet wide. His wings felt light; he ran forward to test their lift, and he thought to amuse himself by jumping the ditch. The result is thus expressed in his own words:[25]
“So I took a good run across the road and jumped at the ditch. But, oh, horrors; once across the ditch my feet did not come down to earth; I was gliding on the air, and making vain efforts to land; for my aëroplane had set out on a cruise. I dangled only one foot from the soil, but, do what I would, I could not reach it, and I was skimming along without the power to stop. At last my feet touched the earth; I fell forward on my hands; broke one of my wings, and all was over; but goodness, how frightened I had been! I was saying to myself that if even a light wind-gust occurred, it would toss me up 30 to 40 feet into the air, and then surely upset me backward, so that I would fall on my back. This I knew perfectly, for I understood the defects of my machine. I was poor, and I had not been able to provide myself with a more complete aëroplane. All’s well that ends well. I then measured the distance between my toe marks, and found it to be 138 feet.
“Here is the rationale of the thing. In making my jump I acquired a speed of 11 to 14 miles per hour, and just as I crossed the ditch I must have met a puff of rising wind. It probably was traveling some 8 to 11 miles per hour, and the two speeds added together produced enough pressure to carry my weight.”