A still more ambitious helicopter was that shown in Fig. 37 invented by Professor Forlanini, an Italian Civil Engineer, and launched in 1878. The lower screw was fastened to the frame of a steam engine, the upper screw was attached to the crank shaft. Steam was supplied from the globe shown beneath, which was two thirds filled with water, and well heated over a separate fire just before an ascension. As the globe was merely a reservoir of hot water and steam, carrying neither fuel nor furnace, its power waned rapidly. The best flight lasted about twenty seconds, attaining a height of 42 feet. The apparatus weighed 77 pounds, spread 21.5 square feet of screw surface, and lifted about 26.4 pounds per horse power. Many other helicopter models have been tried from time to time, with various sources of power, without, however, yielding any important results beyond those already given. But these were sufficiently encouraging. If a large machine could be made to lift as many pounds per horse power, it would be easy to build one competent to carry a man. That, indeed, has been done on several occasions. Of the various inventors who have built man-lifting helicopters M. Cornu and M. Bréguet, in France, seem to have been first to attain a measure of success. While their machines have raised a passenger directly from the ground, they have not yet maneuvered in horizontal flight with sufficient speed to be of practical service. However, a few helicoptrists in various countries are still industriously at work, and hope eventually to rival the aëroplanists in the mastery of flight. There will doubtless be room in the sky for both. Perhaps also there will be occupation and a mission for both. CHAPTER VIII NINETEENTH CENTURY MAN-FLYERS