Now that these particular experiments are leaving my exclusively private control I will say no more of them than what has been already published in the French press. The test will probably consist of an attempt to enter one of the French frontier towns, such as Belfort, or Nancy, on the same day that the air-ship leaves Paris. It will not, of course, be necessary to make the whole journey in the air-ship. A military railway waggon may be assigned to carry it, with its balloon uninflated, with tubes of hydrogen to fill it, and with all the necessary machinery and instruments arranged beside it. At some station a short distance from the town to be entered the waggon may be uncoupled from the train, and a sufficient number of soldiers accompanying the officers will unload the air-ship and its appliances, transport the whole to the nearest open space, and at once begin inflating the balloon. Within two hours from the time of quitting the train the air-ship may be ready for its flight to the interior of the technically-besieged town.
Such may be the outline of the task—a task presented imperiously to French balloonists by the events of 1870-1, and which all the devotion and science of the Tissandier brothers failed to accomplish. To-day the problem may be set with better hope of success. All the essential difficulties may be revived by the marking out of a hostile zone around the town that must be entered; from beyond the outer edge of this zone, then, the air-ship will rise and take its flight—across it.
Will the air-ship be able to rise out of rifle range? I have always been the first to insist that the normal place of the air-ship is in low altitudes, and I shall have written this book to little purpose if I have not shown the reader the real dangers attending any brusque vertical mounting to considerable heights. For this we have the terrible Severo accident before our eyes. In particular, I have expressed astonishment at hearing of experimenters rising to these altitudes without adequate purpose in their early stages of experience with dirigible balloons. All this is very different, however, from a reasoned, cautious mounting, whose necessity has been foreseen and prepared for.
To keep out of rifle range the air-ship will but seldom be obliged to make these tremendous vertical leaps. Its navigator, even at a moderate altitude, will enjoy a very extended view of the surrounding country. Thus he will be able to perceive danger afar off, and take his precautions. Even in my little "No. 9," which carries only 60 kilogrammes (132 lbs.) of ballast, I could rise, materially aided by my shifting weights and propeller, to great heights. If I have not done so it is because it would have served no useful purpose during a period of pleasure navigation, while it would but have added danger to experiments from which I have sought to eliminate all danger. Dangers like these are to be accepted only when a good cause justifies them.
The experiments above named are, of course, of a nature interesting warfare by land. I cannot abandon this topic, however, without referring to one unique maritime advantage of the air-ship. This is its navigator's ability to perceive bodies moving beneath the surface of the water. Cruising at the end of its guide rope, the air-ship will carry its navigator here and there at will at the right height above the waves. Any submarine boat, stealthily pursuing its course underneath them, will be beautifully visible to him, while from a warship's deck it would be quite invisible. This is a well-observed fact, and depends on certain optical laws. Thus, very curiously, the twentieth century air-ship must become from the beginning the great enemy of that other twentieth century marvel—the submarine boat—and not only its enemy but its master. For, while the submarine boat can do no harm to the air-ship, the latter, having twice its speed, can cruise about to find it, follow all its movements, and signal them to the warships against which it is moving. Indeed, it may be able to destroy the submarine boat by sending down to it long arrows filled with dynamite, and capable of penetrating to depths underneath the waves impossible to gunnery from the decks of a warship.
[CHAPTER XXIV]
PARIS AS A CENTRE OF AIR-SHIP EXPERIMENTS
After leaving Monte Carlo, in February 1902, I received many invitations from abroad to navigate my air-ships. In London, in particular, I was received with great friendliness by the Aéro Club of Great Britain, under whose auspices my "No. 6," fished from the bottom of the bay of Monaco, repaired and once again inflated, was exhibited at the Crystal Palace.
From St Louis, where the organisers of the Louisiana Purchase Centennial Exposition had already decided to make air-ship flights a feature of their World's Fair in 1904, I received an invitation to inspect the grounds, suggest a course, and confer with them on conditions. As it was officially announced that a sum of 200,000 dollars had been voted and set apart for prizes it might be expected that the emulation of air-ship experimenters would be well aroused.