6 REPORT OF THE SECRETARY. 



The writer has, during the intervals of his official duties, continued 

 to experiment in this manner, until he has reached a measure of success 

 which seems to justify him in making the statement here that mechan- 

 ical flight has now been attained. 



On the 6th of May last a mechanism built chiefly of steel and driven 

 by a steam engine made two flights each of over half a mile. 1 In each 

 case the process was wholly mechanical, there being no support from 

 gas, but on the contrary the machine being a thousand or more times 

 heavier than the air in which it was made to move. Of the first of these 

 flights I beg to give a statement by an eyewitness, Mr. Alexander 

 Graham Bell, which was communicated in French to the Academie des 

 Sciences of the Institut de France, and which appeared as follows in 

 Nature : 



EXPERIMENTS IN MECHANICAL FLIGHT. 



I have been for some years engaged in investigations connected with aerodromic 

 problems, and particularly with the theoretical conditions of mechanical flight. A 

 portion of these have been published by me under the titles, "Experiments in aero- 

 dynamics" and "The internal work of the wind," but I have not hitherto at any 

 time described any actual trials in artificial flight. 



With regard to the latter, I have desired to experiment until I reached a solution 

 of the mechanical difficulties of the problem, which consist, it must be understood, 

 not only in sustaining a heavy bodj' in the air by mechanical means (although this 

 difficulty is alone great), but also in the automatic direction of it in a borizontal and 

 rectilinear course. These difficulties have so delayed the work that in view of the 

 demands upon my time, which render it uncertain how far I can personally conduct 

 these experiments to the complete conclusion I seek, I have been led to authorize 

 some account of the degree of success which has actually been attained, more par- 

 ticularly at the kind request of my friend, Mr. Alexander Graham Bell, who has 

 shown me a letter which he will communicate to you. In acceding to his wish, and 

 while I do not at present desire to enter into details, let me add that the aerodrome, 

 or "flying machine" in question, is built chiefly of steel, and that it is not supported 

 by any gas, or by any means but by its steam engine. This is of between 1 and 2 

 horsepower, and it weighs, including fire grate, boilers, and every moving part, less 

 than 7 pounds. This engine is employed in turning aerial propellers which move the 

 aerodrome forward, so that it is sustained by the reaction of the air under its sup- 

 porting surfaces. 



I should, in further explanation of what Mr. Bell has said, add that owing to the 

 small scale of construction no means have been provided for condensing tbe steam after 

 it has passed through the engine, and that, owing to the consequent waste of water, 

 the aerodrome has no means of sustaining itself in the air for more than a very short 

 time — a difficulty which does not present itself in a larger construction, where the 

 water can be condensed and used over again. The flights described, therefore, were 

 necessarily brief. 



S. P. Langley. 



Through the courtesy of Mr. S. P. Langley, Secretary of the Smithsonian Institu- 

 tion, I have had on various occasions the privilege of witnessing his experiments 

 with aerodromes, and especially the remarkable success attained by him in experi- 

 ments, made on the Potomac River on Wednesday, May 6, which led me to urge him 

 to make public some of these results. 



I had the pleasure of witnessing tbe successful flight of some of these aerodromes 

 more than a year ago, but Professor Langley's reluctance to make the results public 



1 Since tbe preparation of this report this result has been nearly doubled. 



