WINGS OVER THE SEA — BLERIOT 455 



Since there are now constructed, according to the principles bor- 

 rowed from aviation, fusiform trains and also aerodynamic pilot 

 houses, it may be said that the air resistance, for equal speeds, would 

 be practically the same for the means of transportation on the 

 ground as for the airplane. But it is not the same for the resistance 

 due to the weight to be transported. 



For an automobile, the resistance to horizontal motion, or resist- 

 ance to rolling, is about 25 kilograms per ton; for railroad trains 

 and great steamships, it is about 2 kilograms per ton. Now, in avia- 

 tion, this coefficient is infinitely greater; it corresponds inversely 

 to the superiority of the wing structure. In spite of all the progress 

 of aerodynamics, the necessary traction is at least one-twentieth of 

 the weight to be transported, say 50 kilograms per ton. It is there- 

 fore twice as great as for the automobile, 25 times as great as for the 

 railroad train and the ship. If we see great efforts already being 

 made to lighten rolling stock, this lightening becomes a necessity in 

 aviation, where the dead weight is brought to life; it has a good 

 appetite, for it needs a large ration of fuel. 



For the airplane it is necessary that the ratio of useful pay load 

 to dead weight be at least 20 percent, if it is not to fall into the 

 class of excessively high-priced transportation. I must admit that 

 for the mail plane we can be content with much less, but it should 

 not be supposed that we will always carry the mail at a tariff of 

 2,000,000 francs a ton, as is the case at present for the France-South 

 American mail. This mail will become lighter, for soon it will be 

 divided among the countries located on the same route, and more 

 and more it will be subject to the competition of the radio. 



It will therefore be necessary to consider a less remunerative 

 freight. The difficulty for the great ocean routes will then be to 

 reserve for this freight at least 20 percent of the weight of the air- 

 plane. In this case, as it is necessary to count on about 60 percent 

 for the weight of the airplane and of its motors and equipment, there 

 would remain therefore only 20 percent for the weight of the fuel; 

 this would limit the hops to about 1,500 kilometers, which can now 

 be accomplished at speeds of 200 to 250 kilometers per hour. 



FREQUENCE 



Aviation need only construct units with a capacity of 20 to 25 

 passengers which would be sufficiently comfortable for a trip of 

 several hours. The transport plane, therefore, can be full on each 

 of its trips, even if these trips are daily, while a steamship with a 

 capacity of 2,000 is not assured of having its full complement of 

 passengers on each of its weekly trips. 



