SCIENTIFIC BALLOONING. 309 



years. He speaks of the realm of air, his future hunting ground, as 

 the "great laboratory of changes which contain the germ of future 

 discoveries open to the chemist and meteorologist, as teaching the rela- 

 tion to life of different heights, and as holding within its nameless 

 shores a thousand discoveries to be developed in the hands of physi- 

 cists.' 7 We shall have occasion repeatedly to refer to his methods and 

 the harvest of results secured by his researches. 



A word should here be said as to the capabilities of a balloon as a 

 craft to navigate the sky, and it should be remarked that Mr. (rlaisher 

 himself was fully persuaded of the futility of any self-contained mode 

 of steering. A vast amount of ingenuity and speculation had been 

 bestowed upon this problem, which, experimenters had failed to see, 

 admits of no solution. It is easy to understand how theorists might 

 start on false premises and entertain conceptions that were hopeless of 

 fulfillment. A bird Hies at will through the air, a fish directs its own 

 course in the stream ; hence it was urged that a balloon should be 

 capable of guidance. The essential point overlooked was the radical 

 difference between a creature endowed with enormous natural powers 

 of propulsion relative to its size and an inert balloon in the nature of 

 which the application of adequate mechanical power is an impos- 

 sibility. 



Let us examine the two cases. A salmon impelled by the exigen- 

 cies of nature will swim for miles against the force of a mountain 

 stream, and even leaping the waterfall will stem and struggle through 

 the very torrent falling headlong from above. But conceive the fish's 

 bulk compelled to assume the spherical form of a balloon and the 

 creature at once acquires an irresistible tendency to gyrate, while to 

 proceed in any way different from the rate and direction of the stream 

 would need its muscular exertion increased a hundredfold. On the 

 other hand, conceive a balloon of given capacity built on the lines of 

 a fish, and a moment's consideration will show that you have then 

 only a perfectly unwieldy craft of inordinate length, and, on the very 

 face of it, more completely than ever at the mercy of the wind. Given 

 a balloon poised and in dead calm, and theoretically the aeronaut could 

 propel it in any direction by the mere aid of a lady's fan, but " when 

 the breezes blow " the machine becomes simply an integral part of the 

 general drift, like the leaf in the stream, and is hurried onward 

 literally op the wings of the wind. It needs no pointing out that a 

 ship under sail bears no analogy soever to a free balloon. The ship is 

 propelled by the motion of the air, while it is held under control and 

 guidance by the restraint of the water ; but furnish a balloon with 

 both sails and rudder and, freely in the wind, it is obvious that the 

 first will add nothing to its speed, and the second will in no way affect 

 its course. 



In the one case only of when a balloon is flying so low that a trail 

 rope can be made to drag on the ground, it can be and has been made 



