344 THE BORDERLAND OF SCIENCE. 



be maintained, and should admit of being increased. 

 There must be the means of increasing the elevation, 

 however slowly. There must be the means of guiding 

 the aeronaut's flight. And lastly, the aeronaut or the 

 flying machine must fly with well-preserved balance 

 the supporting power of the air depending entirely on the 

 steadiness with which the supporting surfaces traverse it. 

 I believe that these difficulties are not insuper- 

 able; and not only so, but that none of the failures 

 recorded during the long history of aeronautical 

 experiments need discourage us from hoping for even- 

 tual success. Nearly all those failures have resulted 

 from the neglect of conditions which have now been 

 shown to be essential to the solution of the problem. 

 Nothing but failure could be looked for from the 

 attempts hitherto made ; and, indeed, the only wonder 

 is that failure has not been always as disastrous as in 

 the case of Cooking's ill-judged descent. If a man 

 who has made no previous experiments will insist on 

 jumping from the summit of a steeple, with untried 

 wings attached to his arms, it cannot greatly be won- 

 dered at that he falls to the ground and breaks his 

 limbs, as Allard and others have done. If, notwith- 

 standing the well-known weakness of the human breast- 

 muscles, the aeronaut tries to rise by flapping wings 

 like a bird's, we cannot be surprised that he should fail 

 in his purpose. Nor again can we wonder if attempts to 

 direct balloons from the car should fail, when we know 

 that the car could not even be drawn with ropes 

 against a steady breeze without injury to the supporting 



