140 SOME AEKONAUTICAL EXPERIMENTS. 



responding- quickly to the slightest motion of the rudder. With these 

 glides our experiments for the year 1900 closed. Although the hours 

 and hours of practice we had hoped to o})tain tinall}' dwindled down to 

 about two minutes, we were very much pleased with the general results 

 of the trip, for, setting out as we did, with almost revolutionary theo- 

 ries on many points and an entirely untried form of machine, we con- 

 sidered it quite a point to be able to return without having our pet 

 theories completely knocked in the head by the hard logic of experi- 

 ence, and our own brains dashed out in the l)argain. Everything 

 seemed to us to confirm the correctness of our original opinions, (1) that 

 practice is the key to the secret of flying; (2) that it is practicable to 

 assume the horizontal position ; (3) that a smaller surface set at a negative 

 angle in front of the main bearing surfaces, or wings, will largely count- 

 eract the efi^ect of the fore and aft travel of the center of pressure; (1) 

 that steering up and down can be attained with a rudder without mov- 

 ing the position of the operator's ))ody; (5) that twisting the Avings so 

 as to present their ends to the wind at dift'erent angles is a more prompt 

 and efficient way of maintaining lateral equilibrium than shifting the 

 body of the operator. 



When the time came to design our new machine for 1901, we decided 

 to make it exactly like the previous machine in theory and method of 

 operation. But as th<>, former machine was not able to support the 

 weight of the operator when flown as a kite, except in very high 

 winds and at very large angles of incidence, we decided to increase 

 its lifting power. Accordingly, the curvature of the sui'faces was 

 increased to 1 in 12, to conform to the shape on which LilienthaFs 

 table was based, and to he on the safe side we decided also to increase 

 the area of the machine from 165 square feet to 30S square feet, 

 although so large a machine had never l)efore ])een deemed con- 

 tr()llal)le. The Lilienthal machine had an area of 1.51 scpiare feet, 

 that of Pilcher 1(55 square feet, and the Chanute double-decker 131 

 s(|uare feet. As our system of control consisted in a manipulation of 

 the surfaces themselves instead of a shifting of the operator's body, 

 we hoped that the new machine would l)c controllable, notwithstand- 

 ing its great size. According to calculations, it would o])tain support 

 in a wind of 17 miles per hour with an angle of incidence of only 3 . 



Our experience of the previous year having shown the necessity 

 of a suitable l)uilding for housing the niachin(\ we erected a cheap 

 frame building, 1(5 f(H't wide, 25 feet long, and 7 feet high at the 

 (Mives. yVs our machine was 22 feet wide, 11 feet long (including the 

 iiiddcr). :ui<l al>out t! feet high, it was not necessary to take the ma- 

 chine apart in any way in order to house it. Both ends of the build- 

 ing, except the gable parts, were made into doors, which hinged 

 above, so that wIkmi ()})(Mied they formed an awning at each end and 

 left an entrance the full width of the building. We went into camp 

 al)out the middle of July, aiul were soon joined by Mr. E. C. Ilufl'aker, 



