SCIENTIFIC PROBLEMS OF THE FUTURE. 671 



Thus, if a steamer with a given horsepower will run at say 14 knots an 

 hour, if we double that horsepower we may only succeed in driving her 

 some 16 knots more or less — that is, the doubling of the horsepower will 

 only give us one-seventh additional increase in speed. But in aerial 

 locomotion the conditions are radically different, and the gain is all the 

 other way. Thus, if a flying machine with a given horsepower will run 

 at say 50 miles an hour, with less than double that horsepower it will 

 be likely to run 100 miles, so that the increased power required for 

 doubling the speed is most moderate, instead of being enormous and 

 XDrohibitory as it would be in water trans^jort. 



The aerial navigation of the future will not only be much swifter and 

 more direct, being in a straight course over moor, mountain, or bog, wood, 

 ravine, or river, but it will also be much safer than our ordinary locomo- 

 tion by railway and steamer at present. For as the traffic on our rail- 

 ways and steamboats steadily increases, the risk of accident on the 

 crowded lines and ocean thoroughfares, due to a set of objects all 

 moving in one horizontal plane, increases continually, as we are already 

 finding out in many a disastrous collision. But once let this problem of 

 stable suspension in the air be satisfactorily solved, and we shall cut 

 oft' at a stroke a whole host of causes and possible contingencies which 

 now inevitably involve continual risk of accident. For the flying 

 machine of the future will travel directly and independently through 

 the air from point to point. It will incur no risks from drowsy or over- 

 worked signalmen, from inevitable imperfections in or obstructions upon 

 the permanent Avay, from chances and contingencies due to the running 

 of excursion trains or extra traffic, from icebergs, or floating hulks, rocks, 

 shoals, treacherous currents, unreliable compasses, or other hindrances 

 to safe navigation. If it meet or overtake a fellow machine in the air, 

 it has the whole wide ocean of air above or below it in which to pass in 

 safety, besides an unlimited field on either hand. An endless number 

 of external sources of accident will be eliminated. Once let the flying 

 machine be stable, strong, safe, and powerful enough for its work, and 

 it will represent the safest kind of locomotion ever invented. 



It will compete with the railways for light traffic, such as the trans- 

 port of mails, on terms which must apparently confer an overwhelming 

 advantage. Thus, if "we roughly set the cost of the stations along 100 

 miles of our English railways, and the cost, working, maintenance, and 

 renewal of the aerial machines against the corresponding charges for 

 engines, rolling stock, and working expenses on the line, we have the 

 following advantages to score to the aerial line : 



Annual interest at, say, r> per cent on the first cost of 100 miles of line at 

 £39,000 a mile, which has been about the average cost of construction of 

 English railways £ 195, 000 



Annual charge for maintenance or renewal of the permanent way, at £231 

 per mile = 23, 100 



Total 218.100 



