672 SCIENTIFIC PROBLEMS OF THE FUTURE. 



This shows that in aid of the inainteuauce and working of 100 miles 

 of aerial line, or as increased dividends to the shareholders, there will 

 be an annnal subsidy of more than £200,000, representing the saving 

 on the cost of a corresponding length of railway. It will be seen that 

 the gain is so great that it is scarcely credible that any possible increase 

 in the working expenses of the aerial line, as compared with the cor- 

 responding charges on the railway, could swallow it up. 



The revolution made in locomotion by the flying machine, whereby 

 we shall be able to run from London to New York in perhaps from 

 thirty-six to forty-eight hours, and from London to Paris and back 

 between breakfast and luncheon, will be at least as great as that caused 

 recently by the introduction of railways and steam navigation. 



I can not go into the principles of construction of these aerial machines 

 further than to say, as I have already said elsewhere in a professional 

 publication, that they will probably be of very moderate size, much 

 less than the huge navigable balloon for military purposes, for Miiich 

 they will be most valuable, and will be speedily adopted. For ordinary 

 or civil purposes also they will no doubt be small at first, but it is im])os- 

 sible to set limits to their future development. The web, or superposed 

 webs, of aeroplane, part steadying, part sustaining, which will be their 

 leading external feature, will be inclined during flight at a very small 

 angle with the horizon tal, probably not more than lA to lf°. Inside 

 this, or below it, there will be a long low car, presenting a minimum 

 surface to the air, in which j^assengers, light baggage, or mails will be 

 carried. And the machines will run, as above, at a tremendous pace, 

 probably up to, or even exceeding, 100 miles an hour. 



Finally, I repeat that if anything like the same rate of progress is 

 to be maintained during the next ten or fifteen years as has actually 

 been made during the last ten or fifteen years, the problem of aerial 

 imvigation by flying machines, which ten years ago was tlemonstrably 

 insuperable in the then condition of mechanics, and which at present 

 is very difficult, if not altogether impossible, will soon be comparatively 

 easy, and will be morally certain of solution. 



II. 



A wise man of old, in naming three things which puzzled him, 

 associated together "the way of a fish in the sea" and "the way of a 

 fowl in the air." It is here proposed to follow his example, and, having 

 disposed of the way of the fowl in the air in discussing the question of 

 aerial navigation, to consider next whether any important new depar- 

 tures are not possible and even probable in marine locomotion. I believe 

 they are quite possible and probable, whether in the immediate or in 

 the more remote future. Any revolution which may be effected in this 

 direction will not be as startling and wonder-provoking as the con- 

 quest of the air. Nevertheless, such a future conquest of the water, 

 as we may ])erhaps caU it, may prove ultimately to be of very great 

 importance. 



