AERONAUTICS. 



243 



tlie movements of the wing as simple as possible, I was 

 induced to devise a form of pinion, which for the. sake of dis- 

 tinction I shall designate the Compound Wave Wing. This 

 wing consists of two wave wings united at the roots, as 

 represented at fig. 126. It is impelled by steam, its centre 



being fixed to the head of the piston by a compound joint 

 {x), which enables it to move in a circle, and to rotate along its 

 anterior margin (abed; A, A') in the direction of its length. 

 The circular motion is for steering purposes only. The wing 

 rises and falls with every stroke of the piston, and the move- 

 ments of the piston are Cjuickened during the down stroke, 

 and slowed during the up one. 



During the up stroke of the piston the wing is very 

 decidedly convex on 'its upper surface {abed; ^,^'), its 

 under surface being deeply concave and inclined obliquely 

 upwards and forwards. It thus evades the air during the up 

 stroke. During the down stroke of the piston the wing is 

 flattened out in every direction, and its extremities twisted 

 in such a manner as to form two screws, as shown at a' b' c d!; 

 ^ f g' li; B^B of figure. The active area of the wing is by 

 this means augmented, -the wing seizing the air with great 

 avidity during the down stroke. The area of the wing may 

 be still further increased and diminished during the down 

 and up strokes by adding joints to the body of the wing. 



-m 



Fig. 126- 



