18 



Aerial JVavigation. 



axles EE, ee, advancing towards, and receding from each otheF 

 equally. JJ andj?}' represent two strong rods which connect, or are 

 fastened to the two strong semi-circular rods G^, G^, at equal dis- 

 tances from their center. L represents the car which is firmly fas- 

 tened to the rods 33, jj, at their center. Ff represent the space be- 

 tween the wings, which the aeronaut or their mover occupies, who 

 is to stand upright in the car and take hold of the handles of the 

 wings, K, k, or the middle of their sides BFB, bfb, on each side of 

 him, when he wishes to move them. Having now illustrated one ap- 

 plication of the principle of a balance to the motion of wings, and 

 the manner of constructing them, I shall now proceed to illustrate 

 another, on the best possible construction, before I explain how they 

 are moved. 



Figure 2. 



E 



Figure 2. — I, J, K, L, M, N, O, P represent strong flattened shafts. 

 The circular jagged hne, EFGH, represents a strong spiral wire, 

 which is to be fastened to the circumferential ends of all the flattened 

 shafts, efgh represent a light, strong hoop to which the other ends 

 of the flattened shafts are to be firmly connected by hinges or small 

 staples so as to admit of motion upwards and downwards ; its size 



