It is now generally admitted that the balloon as a means of transit from place to place is essentially uncontrollable, and this remark applies in an almost equal degree to buoyant gas bags of whatever form. The main reason of this is obvious, viz., that, as regards horizontal, or even oblique progression, it is due to the great bulk offered to the wind (so much sail surface really), with which the vehicle must drift helplessly. This inevitable drifting no motor nor mechanism that the balloon will lift can counteract or cope with.

The question which I propose to consider in the following pages is a very old one, and one which is almost universally answered with a confident negative. It is this: “Can man imitate the flight of birds by means of a machine set in motion by his own muscular power?” For the sake of brevity, I will call this the problem of man-flight. As I have said, the great majority of people will answer at once, “No,” and will give as their reason the alleged fact that man has not enough power. The fact that a man can raise himself by means of a ladder seemed, however, to me to prove that he is possessed of sufficient power, the difficulty or impossibility of the problem lying in the difficulty or impossibility of constructing an apparatus which should be at the same time reasonably light, and yet take firm hold of the air. In considering this question, the first thing to be done was evidently to ascertain the power a man can exert.

The remarks made in this paper are due to the action of the United States Patent Laws, as interpreted by one of the examiners, whose duty it was to adjudicate upon the practicability of an invention submitted to him, and whose decision was adverse to the granting of a patent. Protection was solicited for an improvement upon a previously patented mechanical aërial machine, the success of which had been proved by the inventor through the action of a model. The patent was refused on account of the alleged impracticability of the invention owing to the absence of gas as a supporting, or partly supporting, medium. Total misapprehension of the principles of flight is displayed whenever the balloon is recommended to take off part of the weight of any mechanical arrangement. However successfully the pure mechanical action may have proved itself in the conveyance of weights in the air whilst in the model form, the principle seems to be distrusted by some when proposed for extreme weight. But it fortunately happens that the resistance of the air to a body in motion, upon which we depend for success, bears a greatly increasing ratio to the extent of surface which that body assumes.