456 THE EMFIKE OF THE AIR. 



usual tension. When tbey encounter a pressure jj;Teater tluin usual, 

 the tips yield, swinin' to the rear, and automatically perform the nec- 

 essary manceuver. 



In mechanical aeroplaues it will be indispensable, and very easy, to 

 iniitate nature in this act; two springs of calciilated strength, main- 

 taining the wings in the i)Osition of ordinary equipoise, might very 

 well answer the purpose. 



It follows from the facts just stated that it is probable that birds often 

 sail unconsciously. This is the conclusion resulting from attentive 

 observation. Whosoever has closely watched sailing birds will infer 

 that during three-fourths of the time they expend neither force nor will 

 power, that direct action on the part of the creature only occurs when 

 he makes a decision, such as to change his gait or his direction. 



This line of thought leads us to fancy that the soaring birds sleep on 

 the wing. Assuredly uo bird actually goes dead to sleep during flight, 

 yet those sufficiently gift(>d to spend six or eight hours in the air for no 

 particular purpose must reach a state nearly approaching slumber, and 

 Avhich must be very restful. This may resemble the slumber of the 

 horse while standing, in which he still retains sufficient control over his 

 muscles to i)reserve the e([ui])oise on his four legs. 



How far will automatic mechanism permit man to progress with his 

 aeroplanes! It is easy to foresee, at first glance, that he need take 

 action only when first starting, upon reaching decisions, and in final 

 alighting; the rest of the time his faculties maybe otherwise occupied, 

 and it is quite certain that mere support will be attained without com- 

 pelling him to intervene at eacli instant. 



MAIS -FLIGHT THEORETICALLY CONSIDERED. 



Is the reader then to infer that the author has dared to dream of 

 surpassing nature in aerial evolutions'? It is certain that before talking 

 of iml)ro^'ing upon nature, it would be more becoming to make an at- 

 tempt to imitate her; not as a lord of creation, but as an humble adept. 

 Yet, as the author has seriously contemplated producing a larger bird 

 than any existing in nature, and as there may be some value in his 

 thinkings, uotwithstandiug the deficiency of experiments, he will enter 

 upon the question of possible man-flight. 



We are led to consider this question by nature herself; she occasion- 

 ally lifts a corner of the veil through certain evolutions of her favorite 

 children. In point of fact, when we continually observe the sailing 

 birds, when we expend on this study nuich time, much action, and much 

 thought, we are rewarded once in a while — rarely, itis true — by the sight 

 of some mauttuiver which sets us to dreaming of its imitation. 



We say to ourselves upon observing it: But why does not the bird, 

 instead of fatiguing himself by wheeling, rowing or struggling as he 

 generally does, always employ his present evolution, so economical of 

 force ? 



