2 SMITHSONIAN CONTBEBUTIONS TO KMiui.KDGE VOL. 27 



being more or less imperfect, were al firsl intended not for publication, but for 

 my own information on matters where even an incomplete knowledge was better 

 than the absence of any. 



It is to be remembered thai the mechanical difficulties of artificial flight 

 have been so great that, so far as is known, never at any time in the history 

 of the world previous to my experiment of May, 1896, had any such mechanism, 

 however actuated, sustained itself in the air for more than a few seconds — 

 never, for instance, a single half-minute — and those models which had sustained 

 themselves for these few seconds, had been in almost every case actuated by 

 rubber springs, and had been of such a size that they should hardly be described 

 as more than toys. This refers to actual flights in free air, unguided by any 

 t lack or arm, for, since the most economical flight must always be a horizontal 

 one in a straight line, 3 * the fact that a machine has lifted itself while pressed up- 

 ward against an overhead track which compels the aerodrome to move horizon 

 tally and at the proper angle for equilibrium, is no proof at all of real " flight." 



I desire to ask the reader's consideration of the fact that even ten years 

 ago, 4 the whole subject of mechanical flight was so far from having attracted 

 the general attention of physicists or engineers, that it was generally considered 

 to be a field fitted rather for the pursuits of the charlatan than for those of the man 

 of science. Consequently, he who was bold enough to enter it, found almost none 

 of those experimental data which are ready to hand in every recognized ami 

 reputable field of scientific labor. Let me reiterate the statement, which even 

 now seems strange, that such disrepute attached so lately to the attempt to 

 make a " flying machine," that hardly any scientific men of position had made 

 even preliminary investigations, and that almost every experiment to be made 

 was made for the first time. To cover so vast a field as that which aerodromics 

 is now seen to open, no lifetime would have sufficed. The preliminary experi- 

 ments on ihe primary question of equilibrium and the intimately associated 

 problems of the resistance of the sustaining surfaces, the power of the engines, 

 the method of .their application, the framing of the hull structure which held 

 these, the construction of the propellers, the putting of the whole in initial 

 motion, were all lw be made, and could not be conducted with the exactness which 

 would render them final models of accuracy. 



T beg the reader, therefore, to recall as he reads, that everything here has 

 been done with a view to putting a trial aerodrome successfully in flight within 

 a \'c\v years, and thus giving an early demonstration of the only kind which is 

 conclusive in the eyes of Ihe scientific man, as well as of the general public — a 

 demonstration that mechanical flight is possible — by actually flying. 



All that has been done, has been with an eye principally to this immediate 



1 In this statement, nf course, no account is taken of the " interna] work of the wind." 

 1 Ten years prior to 1S97. 



