THE FIRST MAN-CARRYING AEROPLANE CAPABLE OF 
SUSTAINED FREE FLIGHT—LANGLEY’S SUCCESS AS A 
PIONEER IN AVIATION. 
By A. F. Zaum, Ph. D. 
[With 8 plates.] 
Tt is doubtful whether any person of the present generation will 
be able to appraise correctly the contributions thus far made to the 
development of the practical flying machine. The aeroplane as it 
stands to-day is the creation not of any one man, but rather of three 
generations of men. It was the invention of the nineteenth century; 
it will be the fruition, if not the perfection, of the twentieth century. 
During the long decades succeeding the time of Sir George Cayley, 
builder of aerial gliders and sagacious exponent of the laws of flight, 
continuous progress has been made in every department of theoreti- 
cal and practical aviation—progress in accumulating the data of 
aeromechanics, in discovering the principles of this science, in im- 
proving the instruments of aerotechnic research, in devising the or- 
gans and perfecting the structural details of the eden dynamic 
flying machine. From time to time numerous aerial craftsmen have 
flourished in the world’s eye, only to pass presently into comparative 
obscurity, while others too neglected or too poorly appreciated in their 
own day subsequently have risen to high estimation and permanent 
honor in the minds of men. 
Something of this latter fortune was fated to the late Secretary of 
the Smithsonian Institution. Fora decade and a half Dr. Langley had 
toiled unremittingly to build up the basic science of mechanical flight, 
and finally to apply it to practical use. He had made numerous model 
aeroplanes propelled by various agencies—by India rubber, by steam, 
_ by gasoline—all operative and inherently stable. Then with great 
confidence he had constructed for the War Department a man flier 
which was the duplicate, on a fourfold scale, of his successful gaso- 
line model. But on that luckless day in December, 1903, when he 
expected to inaugurate the era of substantial aviation, an untoward 
accident to his launching gear badly crippled his carefully and ade- 
quately designed machine. The aeroplane was repaired, but not 
again tested until the spring of 1914—-seven years after Langley’s 
death. 
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