It may be generally known, that for some time extraordinary efforts have been making to discover a method by which locomotion through the air may be rendered as certain and practicable as locomotion by sea or land. In this desperate enterprise, of bringing the principle of aërostation into regular use, certain individuals in Paris have taken the lead. Our belief, like that of others, is, that plans of this kind will fail, as they have hitherto done; at the same time, we think it would be improper to dogmatise on the subject, and will only say, that if travelling by balloon becomes one of the established things of the day, so much the better.
With these feelings, we have thought it consistent with our duty as journalists, not to refuse publicity to an account of what was till lately doing in Paris to forward practical aërostation—we say, lately; for we are told by our correspondent, that the operations towards perfecting the invention have been stopped by orders of the French government, from an opinion that, if air-travelling were introduced, it would be injurious to the custom-house, and denationalise the country. This resolution of the French government is to be regretted, not less on the score of science, than from the ruin it has inflicted on the modest means of the ingenious operator. With these preliminary explanations, we offer the following paper, just as handed to us by a respectable party conversant with the details to which he refers.
'The chief difficulty in aëro-locomotion, is that of steering; because the atmosphere seems to present no substantial fulcrum which can be pushed against. But that this difficulty is not altogether insurmountable, is evident from the single fact, that birds really do steer their way through the air. This fact suggests, that a fulcrum is not necessarily a palpable substance: it may be pliant or movable. For instance, if we fasten the string of a kite to a ball, this ball, which represents the fulcrum, being set in motion by the kite, becomes a movable fulcrum: a child also, holding the string in his hand, runs from right to left without impeding the motion of the kite, of which motion he is the movable fulcrum. Absolute stability, therefore, is not a necessary condition of a fulcrum; it is sufficient that there be, between the resistant force and the motive force, a difference of intensity in favour of the former. Thus, in water, the fulcrum, being liquid, is necessarily pliant and movable; yet it is quite possible, as every child knows, to obtain in this element purchase sufficient to steer the largest ships.
'In the air, which is a gas, the fulcrum being gaseous, must also be movable; but although the air, being the most elastic body with which we are acquainted, is therefore the least apt to furnish a fulcrum, yet, as compressed air is capable of bursting the strongest metallic receptacles, splitting the solid rock, and rending the bosom of the earth, it would seem that we have only to act upon the air through pressure, in order to obtain the requisite purchase from which to steer.
'Foremost among those who are thus endeavouring to render the balloon manageable, is M. Pétin of Paris, who has devoted fifteen years to the study of this subject, the last three years to lecturing upon it in the principal towns of France, and who has unfortunately expended the whole of his resources in constructing an air-ship intended to demonstrate, on a small scale, the possibility of steering according to the system which he has elucidated. We say on a small scale; for though the dimensions of the curious construction in question, intended to carry two hundred passengers, will appear large to those of our readers whose ideas of ballooning have never gone beyond the ordinary ascensions so much in vogue at the present day, they are yet of almost microscopic minuteness when compared with the developments of which M. Pétin and his friends conceive his plans to be susceptible!
'The body of this novel vessel consists of two covered decks, or galleries, connected by a series of narrow bridges, thrown across the open space between them, on a level with their floor; thus forming the body of the vessel, which looks not unlike a couple of Noah's Arks, placed parallel to each other, and connected by means of the aforesaid bridges. Suspended across the upper part of this open space, is a row of sixteen movable wings, placed one behind the other, and attached, by means of pivots, to the upper edge of the inner walls of the galleries; these wings are of oiled sail-cloth, set into oblong iron frames, and are worked by machinery. They may be opened or closed, inclined to or from each other, at any angle, upwards or downwards. At each end of the vessel, near the stem and the stern, is a pair of screws, similar to the propellers of a steam-ship, and worked by a couple of small steam-engines of three horse-power each, one being placed just above and behind each pair of screws. Lastly, attached to masts projecting horizontally from each end of the ship, are a couple of triangular or lateen sails; smaller sails are also attached to the under part of the balloons, which, enclosed in net-work of strong cord, are fastened to the roof of the galleries, directly over the wings, beneath which, again, are the bridges from which the crew are to work the ship.
'These skeleton galleries, which, with the exception of the floors, and the walls and roof of their central portion, are constructed of lattice-work, faced with thin bands of iron, in order to render the whole as light as possible, are 162 feet in length, 8 feet in height by 4 feet in width in their central portion, but taper off to 18 inches in height and width at their extremities. This mode of building gives an oval form to the framework of the vessel. The central portion of the galleries, which is at the same time the highest and the widest, embraces a length of 66 feet, and is appropriated to the passengers. The boilers are placed here also, one in each gallery; the steam being conveyed to the engines by pipes.
'The total length of the ship, including that of the two projecting masts, is 198 feet; and its total weight, including that of the machinery, and a crew of eight men, is 14,000 pounds. The balloons are 66 feet in diameter, and will contain 15,000 cubic yards of gas. Their ascensional force is 20,000 pounds. The wings are 6 feet in length by 15 in width. The screws are made of pitched canvas, rimmed with iron; they are 6 feet in length.
'The eight central wings, disposed in the form of an upright roof—parachute—or of an inverted roof—paramont—are intended, by pressing on the air above in ascending, and on the air below in descending, to furnish the necessary point of resistance, or fulcrum, from which to steer. The other eight wings, four at each end of the central group, are intended, by being opened or shut, to act as a counterpoise; thus producing a rupture of equilibrium around the central fulcrum, and thereby changing the upward movement of the balloons into an oblique forward movement. In other words, the ship being raised into the air—to the stratum immediately above the region of storms—and maintained there by the ascensional force of the balloons, and being forced onward by the screws, the four anterior wings are to be opened, the four posterior ones remaining closed. The forepart of the ship being now relieved from the downward pressure of the air, caused by the upward movement of the balloons, this pressure still acting on the posterior wings, its equilibrium is destroyed; the forepart rises, the hindpart dips, thus changing the direction of the ship's course, by converting its vertical into an oblique movement, which is to carry it onward upon a plane inclined slightly upward.
'This operation is to be followed by its converse. The four posterior wings are to be opened, and the four anterior ones closed; the vessel now dips in the opposite direction, and moves forward on a plane inclined slightly downward; and so on. Thus, by alternately opening and shutting the two sets of lateral wings, M. Pétin proposes to make his ship sail forward on a series of inclined planes, upwards and downwards. He takes care to assure us, however, that the requisite degree of inclination will be so slight as to be imperceptible to his passengers; and instances, in corroboration of this opinion, the beds of rivers, where a very slight degree of inclination suffices to produce a rapid current.