of linnets. Here the physico-theologist, who is accustomed to contemplate the wisdom of God in all his works, might be led to infer that he has caused this deviation from the general method of flying, in order to demonstrate to us the effect of the projectile force, and that it is one of the greatest essentials in the art of flying, and perfectly distinct from, and independent of the continued expansion of wings. :. When we see pigeons flying upwards in the angle of sixty or seventy, as we do every day, from the streets to the tops of houses, with the plane of their wings parallel to the line of their ascent; I think they prove in a satisfactory manner, the great effect of the projectile force; for without we admit this to be the cause of their ascending in such angles, how can we possibly account for it in any other way, upon rational principles Vide plate 4. A stone thrown by the hand, and a ball ejected from the mouth of a cannon, are made to overcome specific gravity, and fly to a great distance; we all know that these are not kept up by wings, but entirely by the projectile force. In fact, it is by the air being made continually to push the bird forwards, which constitutes the main cause of flying. We must attribute to a total ignorance of the fundamental principles, that the art of flying has not been brought hitherto into common practice; for an art, so practicable as it is, must at any period of time have soon succeeded a discovery, such as I have made; and now, that the art appears so very attainable, I hope that every friend to arts and sciences will acknowledge that it ought to have a fair trial. I shall now conclude my treatise on flying with an appeal to the candour and good sense of my readers, whether the arguments I have used, and the principles upon which I have insisted the art of flying may be accomplished, are not such as give it a just claim to their approbation; for I think I may affirm, without being accused of arrogance, that the art of flying has never before been treated of upon such rational and scientific principles.* *I will here take the liberty of communicating a few hints, which I conceive to be of importance to the aerostatic science. Now that we know the true cause of the projectile motion of birds, and I having suggested a plan for producing the same effect by artificial means, we may be able to accomplish what Messrs. Roberts, Blanchard, and others attempted to do, but in vain, entirely from their not possessing a knowledge of this mystery of nature. I am alluding to the steerage of balloons, which they endeavoured, with great labour, to attain, by striking a number of oars horizontally against the air; and if we do but take into consideration that the balloon was constantly flying from the air against which they were striking, it does not seem probable that they could, by such means, produce the effect they aimed at. But if we make a car from the plan which I have laid down in this treatise, and upon a scale large enough to admit of one of Messrs. Mead and Co.'s new invented revolving steam engines, to move the lever with, we then can work, in a vertical direction, a pair of very large wings, which would produce a projectile force sufficient to impel the bal loon forwards in any point of the compass to which we might incline it; and by having a large tail fixed to the car, in an universal joint, we should be able to give it any incli Having now submitted to the good sense of my countrymen, the whole of what I intended on the subject of flying, I, for the present, most respectfully take my leave of them, indulging a hope that the prediction of Bishop Wilkins, expressed in a former page, will soon be verified, and trusting that I shall not be disappointed in the opinion I entertain respecting the patronage which they will extend towards nation whatever; and when we have thus effected a perfect steerage to balloons, we shall be able to convey a number of passengers to any place of destination with accuracy and safety. But for this kind of navigation the balloon must be much smaller than usual, and perfectly spherical, and the gas should be kept in such a degree as not to have too great a tendency to ascend-it should be so regulated as to float in equilibrium with the atmosphere; the aeronauts could then keep the machine at a moderate height-from fifty to a hundred feet would be high enough for ordinary sailing, and if it was found to be inclining too much upwards, it might be counteracted by holding the tail in a descending direction. One of Mr. Mead's patent steam engines can be made with a one horse power, or equal to the strengths of eight or ten men, that will not weigh more than eight stone; and will stand in the small space of four feet by two, with the boiler and all the apparatus belonging to it. the invention now laid before them. Encouraged by the public, I shall not abandon my purpose of making still further exertions to advance and complete an art, the discovery of the true principles of which, I trust, I can with verity affirm to be exclusively my own. Printed by Joseph Simmons, FINIS. |