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第54章

Langley, born in Roxbury, Massachusetts, in 1834, was another link in the chain of distinguished inventors who first saw the light of day in Puritan New England.And, like many of those other inventors, he numbered among his ancestors for generations two types of men--on the one hand, a line of skilled artisans and mechanics; on the other, the most intellectual men of their time such as clergymen and schoolmasters, one of them being Increase Mather.We see in Langley, as in some of his brother New England inventors, the later flowering of the Puritan ideal stripped of its husk of superstition and harshness--a high sense of duty and of integrity, an intense conviction that the reason for a man's life here is that he may give service, a reserved deportment which did not mask from discerning eyes the man's gentle qualities of heart and his keen love of beauty in art and Nature.

Langley first chose as his profession civil engineering and architecture and the years between 1857 and 1864 were chiefly spent in prosecuting these callings in St.Louis and Chicago.

Then he abandoned them; for the bent of his mind was definitely towards scientific inquiry.In 1867 he was appointed director of the Allegheny Observatory at Pittsburgh.Here he remained until 1887, when, having made for himself a world-wide reputation as an astronomer, he became Secretary of the Smithsonian Institution at Washington.

It was about this time that he began his experiments in "aerodynamics." But the problem of flight had long been a subject of interested speculation with him.Ten years later he wrote:

"Nature has made her flying-machine in the bird, which is nearly a thousand times as heavy as the air its bulk displaces, and only those who have tried to rival it know how inimitable her work is, for the "way of a bird in the air" remains as wonderful to us as it was to Solomon, and the sight of the bird has constantly held this wonder before men's minds, and kept the flame of hope from utter extinction, in spite of long disappointment.I well remember how, as a child, when lying in a New England pasture, h watched a hawk soaring far up in the blue, and sailing for a long time without any motion of its wings, as though it needed no work to sustain it, but was kept up there by some miracle.But, however sustained, I saw it sweep in a few seconds of its leisurely flight, over a distance that to me was encumbered with every sort of obstacle, which did not exist for it....How wonderfully easy, too, was its flight! There was not a flutter of its pinions as it swept over the field, in a motion which seemed as effortless as that of its shadow.After many years and in mature life, I was brought to think of these things again, and to.ask myself whether the problem of artificial flight was as hopeless and as absurd as it was then thought to be"...In three or four years Langley made nearly forty models."The primary difficulty lay in making the model light enough and sufficiently strong to support its power," he says."This difficulty continued to be fundamental through every later form; but, beside this, the adjustment of the center of gravity to the center of pressure of the wings, the disposition of the wings themselves, the size of the propellers, the inclination and number of the blades, and a great number of other details, presented themselves for examination."By 1891 Langley had a model light enough to fly, but proper balancing had not been attained.He set himself anew to find the practical conditions of equilibrium and of horizontal flight.His experiments convinced him that "mechanical sustenation of heavy bodies in the air, combined with very great speeds, is not only possible, but within the reach of mechanical means we actually possess."After many experiments with new models Langley at length fashioned a steam-driven machine which would fly horizontally.It weighed about thirty pounds; it was some sixteen feet in length, with two sets of wings, the pair in front measuring forty feet from tip to tip.On May 6, 1896, this model was launched over the Potomac River.It flew half a mile in a minute and a half.When its fuel and water gave out, it descended gently to the river's surface.In November Langley launched another model which flew for three-quarters of a mile at a speed of thirty miles an hour.

These tests demonstrated the practicability of artificial flight.

The Spanish-American War found the military observation balloon doing the limited work which it had done ever since the days of Franklin.President McKinley was keenly interested in Langley's design to build a power-driven flying machine which would have innumerable advantages over the balloon.The Government provided the funds and Langley took up the problem of a flying machine large enough to carry a man.His initial difficulty was the engine.It was plain at once that new principles of engine construction must be adopted before a motor could be designed of high power yet light enough to be borne in the slender body of an airplane.The internal combustion engine had now come into use.

Langley went to Europe in 1900, seeking his motor, only to be told that what he sought was impossible.

His assistant, Charles M.Manly, meanwhile found a builder of engines in America who was willing to make the attempt.But, after two years of waiting for it, the engine proved a failure.

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