AERONAUTICS. 



237 



There is, moreover, a continuous play of the wing; the 

 down stroke gliding into the up one, and vice versa, which 



Fjcx. ^ i 



Fig. 117.— Eepresents a longitudinal section of bamboo cane ten feet long, and 

 one inch wide. — Original. 



Fig. 118 — The appearance presented by the same cane when made to vibrate 

 by the hand. The cane vibrates on either side of a given line {x x), and ap- 

 pears as if it were in two places at the same time, viz., c and /, g and d, e and 

 h. It is thus during its vibration thrown into figures-of-S or opposite curves. 

 — Original. 



Fig. 119. — The same cane when made to vibrate more rapidly. In this case the 

 waves made by the cane are less in size, but more numerous. The cane is seen 

 alternately on either side of the line x a*, being now at i now at m.^ now at n 

 now ati, now at k now at o, now at p now at I. The cane, when made to vi- 

 brate, has no dead points, a circumstance due to the fact that no two parts of 

 it reverse or change their curves at precisely the same instant. This curious 

 reciprocating motion enables the wing to seize and disengage itself from the 

 air with astonishing rapidity. — Original, 



Fig. 120. — The same cane with a flexible elastic curtain or fringe added to it. The 

 curtain consists of tapering v/halebone rods covered with a thin layer of india- 

 rubber, a h anterior margin of wing, c d posterior AMto.— Original. 



Fig. 121. — Gives the appearance presented by the artificial wing (fig. 120) when 

 made to vibrate by the hand. It is thrown into longitudinal and transverse 

 waves. The longitudinal waves are represented by the arrows c cZ ^, and 

 the transverse waves by the arrows / g h. A wing constructed on this 

 principle gives a continuous elevating and propelling power. It developes 

 figure-of-8 curves during its action in longitudinal, transverse, and oblique di- 

 rections. It literally floats upon the air. It has no dead points — is vibrated 

 with amazingly little power, and has apparently no slip. It can fly in an up- 

 ward, downward, or horizontal direction by merely altering its angle of in- 

 clination to the horizon. It is applied to the air by an irregular motion— the 

 movement being most sudden and vigorous always at the beginning of the 

 down stroke. — Original. 



