10 
ADLER. 
lication of an extended memoir in the Smithsonian Contri- 
butions to Knowledge, and third through a brief popular 
article on the possibility of mechanical flight, in the Cen- 
tury Magazine. I alluded above to one of the group of what 
would now be called “captains of industry’’ in Pittsburg 
who had sympathized with Mr. Langley and his work and 
had aided him in its prosecution. The name of this man, 
William Thaw, was commemorated in the preface to “Ex- 
periments in Aerodynamics” in the following phrase, 
“If there prove to be anything of permanent value in these 
investigations, I desire that they may be remembered in con- 
nection with the name of the late William Thaw, whose 
generosity provided the principal means for them,” 
though it should be said that Mr. Thaw’s aid in this di- 
rection was not to be measured alone by money contribu- 
tion to the experiments, for it meant much at that time that 
as eminently a practical man as he should have believed 
in what was then considered a wild idea, and have sup- 
ported a scientific man in it both by money and b}- moral 
encouragement. This memoir, “Experiments in Aero- 
dynamics,” was at once republished in full in French and 
attracted widespread attention. Mr. Langley persevered in 
the study, and in 1893 he issued a second memoir, “The 
Internal Work of the Wind.” This also appeared in Eng- 
lish and French, and was designed to prove that aerial 
1 light had an aid, described as the potentiality in the inter- 
nal work of the wind, which would be of great moment in 
the practical solution of the problem. 
But the painstaking experiments with the whirling table 
and with other forms of apparatus devised by Mr. Langley 
for the study of the question of aerial navigation did not con- 
lent him, and although not himself a mechanical engineer, 
and with very inferior appliances, he took up the building 
of a machine, driven by a steam-engine, which he hoped 
would practically demonstrate the possibility of mechanical 
flight. There were innumerable mechanical difficulties in 
its construction and also in its launching, and, after failures 
