This prodigious machine is directed and guided by a tail seven palmi long, which is attached to the knees and ankles of the inventor by leather straps; by stretching out his legs, either to the right or to the left, he moves the machine in whichever direction he pleases.... The machine’s flight lasts only three hours, after which the wings gradually close themselves, when the inventor, perceiving this, goes down gently, so as to get on his own feet, and then winds up the clockwork and gets himself ready again upon the wings for the continuation of a new flight. He himself told us that if by chance one of the wheels came off or if one of the wings broke, it is certain he would inevitably fall rapidly to the ground, and, therefore, he does not rise more than the height of a tree or two, as also he only once put himself in the risk of crossing the sea, and that was from Calais to Dover, and the same morning he arrived in London.’ And yet there are still quite a number of people who persist in stating that Bleriot was the first man to fly across the Channel! A study of the development of the helicopter principle was published in France in 1868, when the great French engineer Paucton produced his _Théorie de la Vis d’Archiméde_. For some inexplicable reason, Paucton was not satisfied with the term ‘helicopter,’ but preferred to call it a ‘ptérophore,’ a name which, so far as can be ascertained, has not been adopted by any other writer or investigator. Paucton stated that, since a man is capable of sufficient force to overcome the weight of his own body, it is only necessary to give him a machine which acts on the air ‘with all the force of which it is capable and at its utmost speed,’ and he will then be able to lift himself in the air, just as by the exertion of all his strength he is able to lift himself in water. ‘It would seem,’ says Paucton, ‘that in the ptérophore, attached vertically to a carriage, the whole built lightly and carefully assembled, he has found something that will give him this result in all perfection. In construction, one would be careful that the machine produced the least friction possible, and naturally it ought to produce little, as it would not be at all complicated. The new Dædalus, sitting comfortably in his carriage, would by means of a crank give to the ptérophore a suitable circular (or revolving) speed. This single ptérophore would lift him vertically, but in order to move horizontally he should be supplied with a tail in the shape of another ptérophore. When he wished to stop for a little time, valves fixed firmly across the end of the space between the blades would automatically close the openings through which the air flows, and change the ptérophore into an unbroken surface which would resist the flow of air and retard the fall of the machine to a considerable degree.’