178 STORY OF EXPERIMENTS IN MECHANICAL FLIGHT. 



or above tbe wing and to produce the salient difference alluded to. 

 Wlien this was noticed all aerodromes were inverted, and sand was 

 dredged uniformly over the wings until its weight represented that of 

 the machine. The flexure of the wings under those circumstances 

 must be nearly that in free air, and it was found to distort them beyond 

 all anticipation. Here commences another series of trials, in which the 

 wings were strengthened in various ways, but in none of which, with- 

 out incurring a prohibitive weight, was it possible to make them strong 

 enough. Various methods of guying them were tried, and they were 

 rebuilt on different designs — a slow and expensive process. Finally, it 

 may be said, in anticipation (and largely through the skill of Mr. Reed, 

 the foreman of the work), the wings were rendered strong enough with- 

 out excessive weight, but a year or more passed in these and other 

 experiments. 



In the latter part of 1894 two steel aerodromes had already been 

 built, which sustained from 40 to 50 per cent of their dead-lift weight 

 on the pendulum, and each of which was apparently supplied with 

 much more than sufficient power for horizontal flight (the engine and 

 all the moving parts furnishing over one horsepower at the brake 

 weighed in one of these but 26 ounces); but it may be remarked that 

 the boilers and engines in lifting this per cent of the weight did so 

 only at the best performance in the shop, and that nothing like this 

 could be counted upon for regular performance in the open. Every 

 experiment with the launch, when the aerodrome descended into the 

 water, not gently, but impelled by the misdirected power of its own 

 engines, resulted at this stage in severe strains and local injury, so that 

 repairing, which was almost rebuilding, constantly went on; a hard but 

 necessary condition attendant on the necessity of trial in the free air. 

 It was gradually found that it was indispensable to make the frame 

 stronger than had hitherto been done, though the absolute limit of 

 strength consistent with weight seemed to have been already reached, 

 and the year 1895 was chiefly devoted to the labor on the wings and 

 what seemed at first the hopeless task of improving the construction 

 so that it might be stronger without additional weight, when every 

 gram of weight had already been scrupulously economized. With 

 this went on attempts to carry the effective power of the burners, 

 boilers, and engines further, and modification of the internal arrange- 

 ment and a general disposition of the parts such that the wings could 

 be placed further forward or backward at pleasure, to more readily 

 meet the conditions necessary for bringing the center of gravity under 

 the center of pressure. So little had even now been learned about the 

 system of balancing in the open air, that at this late day recourse was 

 again had to rubber models, of a different character, however, from 

 those previously used; for in the latter the rubber was strained, not 

 twisted. These experiments took up an inordinate time, though the 

 flight obtained from the models thus made was somewhat longer and 

 much steadier than that obtained with the Penaud form, and from 



