AERONAUTICS. 



241 



paper. As the layers overlap each other, it follows that there 

 are five layers at the anterior margin {ah), and only one at 

 the posterior (c d). This form of wing is not twisted upon 

 itself structurally, but it twists and untwists, and becomes a 

 true screw during its action. 



Fig. 123. — Artificial Wing with Perpendicular {r s) and Horizontal {t u) Elastic 

 Bands attached to ferrule [w). 



a, b, Strong elastic reed, whicli tapers towards the tip of the wing. 



d, e,f,h,i,j,k, Tapering curved reeds, which run obliquely from the 

 anterior to the posterior margin of the wing, and which radiate towards the 

 tip. 



m, Similar curved reeds, which run still more obliquely. 



d, n, o,p, q, Tapering curved reeds, which run from the anterior margin of 

 the wing, and at right angles to it. These support the two sets of oblique 

 reeds, and give additional strength to the anterior mai:gin. 



X, Ball-and-socket joint, by which the root of the wing is attached to the 

 cylinder, as in fig. 122, p. 239. —Original. 

 Fig. 124.— Flexible elastic wing with tapering elastic reed [ah] running along 

 anterior margin. 



c, d, Posterior margin of wing i, Portion of wing composed of one layer 

 of flexible material, h. Portion of wing composed of two layers, g, Portion 

 of wing composed of three layers /, Portion of wing composed of four 

 layers, e, Portion of wing com loosed of five layers, ic. Ball-and-socket joint 

 at root of wing. — Original. 

 Fig. 125.— Flexible valvular wing with india-rubber springs attached to its 

 root. 



a, h, Anterior margin of wing, tapering and elastic, c, d. Posterior margin 

 of wing, elastic. /,/,/, Segments which open during the up stroke and 

 #close during the down, after the manner of valves. These are very narrow, 

 and open and close instantly, x, Universal joijit. m, Superior elastic 

 band. >?, Ditto inferior, o, Ditto anterior, p, q. Ditto oblique, r, Ring 

 into which the elastic bands are i^xe(l. — Original. 



How to construct a fVave JVing which shall evade the super- 

 imposed Air during the Up Stroke.- — To construct a wing which 



