THE NORTH AMERICAN REVIEW.
mospheric conditions or the length of the course, in selecting the machine, more or less sustained by hydrogen or by the propeller, whichever best responds to his wishes.
For myself, ardently devoted as I am to the captivating study of aviation, I am persuaded that the air-ship, thanks to the hydrogen, will always have an advantage over the aëroplane in being able to carry a great quantity of combustible material for long journeys, a number of travellers, and a considerable weight of merchandise—an advantage which will give it a practical utility unquestionably superior in commerce or in war. On the other hand, the flying-machine will without doubt attain, for short distances, an incomparable speed, the advantages of which will be in certain cases very appreciable—for instance, in crossing a strait like the Strait of Dover, in the journeys of the wealthy, or in the transmission of despatches at a high rate.
But when I think that an air-ship of the length of the Transatlantic steamer "Deutschland," constructed with the proportions of my "No. 6," would transport a thousand voyagers of my own weight, with a sufficiently powerful motor and the necessary amount of petroleum, from New York to Havre in two days, I cannot help finding the dirigible balloon more interesting than the aëroplane from the economic point of view, which is the dominant one in the world of to-day.
This is not the conception of a romancer. It is an affirmation which I can easily make good by figures; and, what is better, it will, I am firmly convinced, within a few years have become an accomplished fact.
Evidently this condition will not make itself, but it will be achieved because there is no conquest to which the entire human race aspires more ardently than to the empire of the air.
To attain this end, a series of tests in the open air will be necessary—tests not contemplated by inventors who, in their distaste for action, confine themselves to sketching vaguely upon paper projects impossible of realization.
Aërial progression will be achieved not in the mysterious recesses of the laboratory, but in the air itself. As the child learns to walk only by trying to walk, so man will learn to fly only by effectually practising flying.
The problem of aerial locomotion, contrary to the tradition which has so long retarded its solution, has no secrets. It de-
