helicopteron

But though many of these projects called forth considerable inventive ability, yet, until quite recently, the helicopteron (from ἑλικός, any thing spiral or twisted, and πτερόν, a wing—that is, a machine furnished with an aërial screw-propeller) was the only type of machine which had succeeded in raising itself in flight. Several of these helicopterons have been constructed since 1784, at which date Bienvenu made the first that flew.[…]Leaving out of consideration the inventions which are evidently defective, we have thought it possible to divide the majority of the systems of artificial flight into helicopterons, areoplanes, and orthopterons (from ὀρθός, straight, and πτερόν, a wing). The helicopterons sustain themselves by the aid of screws whose axes of rotation are nearly vertical.[…]We applied the new motor first to the helicopteron, after having previously investigated the curious and valuable actions of caoutchouc when subjected to various successive torsions.[…]The great superiority of these results over those obtained with preceding helicopterons encouraged us to apply our motor to other systems of artificial flight.[…]Measured directly, and irrespective of any hypothesis, the force required to sustain and propel the areoplane and the helicopteron proved to be relatively moderate, and did not approach the fabulous estimations previously given by Navier.[…]Our helicopterons and areoplanes which performed with success on the 2d of July, 1875, before the Physical Society, have a numerous offspring.