SOARING MACHINES. 213 



long retain the propeller at the proper soaring angle. The 

 machine must sooner or later tip either up or down. The rod 

 with loaded ends and cells can but retard the end tipping long 

 enough to show that the propeller is soaring. For these reasons 

 the weight was transferred to a point below the propeller, thus 

 reverting to the method of maintaining the equilibrium of the 

 balloon or parachute, and which is used by the experimenters with 

 gliding machines. 



The situation and aspect of the tail or weather-cock came under 

 consideration, and it was seen that the nearer it was placed to the 

 after edge of the propeller the more instantaneously would gravity 

 adjust the propeller to the proper angle. It was also recognized 

 that whatever area is given to the weathercock, its longest dimen- 

 sion should be vertical. The meteorologists will think this rank 

 heresy. 



Lancaster points out that the weather-cock should be vertical 

 only; and as far as I know every aeronautical construction ever 

 made but his, has horizontal tail surface. A moment's considera- 

 tion should have shown us that when we wish to preserve the 

 angle of incidence by the action of gravity, as all gliding machines 

 do, any horizontal tail must act as a check to the necessary rapid 

 adjustment. 



Kites M. and N. were therefore remade as shown in Figs. 4, 5, 

 6, 7, and assume a strong likeness to Lancaster's " effigy" described 

 in the Engineer 1882, and which I have endeavoured to reproduce 

 in Fig. 8, from his dimensions given in Chanute's "Progress in 

 Flying Machines," page 199. I can well believe that many of 

 Lancaster's " hundreds of effigies " soared in spite of their flat 

 cardboard surfaces, if 'the stick that extended the wings had some 

 considerable depth and was fastened to the under side of the front 

 edge ; which point is not made clear. 



It is also recorded in the same work at page 197, that his 

 explanation in the American Naturalist was so plainly erroneous 

 that he was harshlv criticised. 



