Airships past and present, together with chapters on the use of balloons in connection with meteorology, photography and the carrier pigeon . nsion, is nolonger sufficient to overcome the resistance of the air. Accordingto this view, the essential feature in the flight of a bird lies in thestate of tension, succeeded by a corresponding state of bird can only fly forward, because the positions of its wingsand of its centre of gravity do not admit of a backward Frenchman, named Marey, also made a special study of thesubject, and found that a bird does not drive the air ba
Airships past and present, together with chapters on the use of balloons in connection with meteorology, photography and the carrier pigeon . nsion, is nolonger sufficient to overcome the resistance of the air. Accordingto this view, the essential feature in the flight of a bird lies in thestate of tension, succeeded by a corresponding state of bird can only fly forward, because the positions of its wingsand of its centre of gravity do not admit of a backward Frenchman, named Marey, also made a special study of thesubject, and found that a bird does not drive the air backwards as itflaps its wings in a downward direction, but flies in such a manneras to bring the tips of the wings towards the front. The tips of 92 AIESHIPS PAST AND PEESENT. the wings do not move as shown at A, but as shown at B. Asthe bird flies forward, it does not drive the air from under itsbody, but throws it, from the side and from behind, beneath thebody ; at the same time the force of the downward blow altersthe shape of the feathers from a downward concavity into anupward convexity. These forces tend to drive the bird forward. Fig. 48.—Stentzels flying machine. in exactly the same way as a fish is propelled by the movementof its tail. There was at any rate a better prospect of success as soon as itwas proposed to use some form of engine as the motive attempts on these lines deserve mention. An engineer,named Stentzel, of Hamburg, constructed a gigantic bird; thedistance between the tips of the wings was 20 ft.; the wingsthemselves were 5 ft. 6 in. broad, and formed a concavity of 1 in12. They were covered with silk, the main ribs being of steel FLYING MACHINES. 93 and joined by small connecting rods to a carbonic acid was intended to steer by means of a rudder, shaped like across. The surface exposed to the air was 87 square feet, and withan output of 1*5 horse-power, a weight of 75 lbs. was lifted fromthe ground. It was possible to make 84 flaps
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Keywords: ., bookcentury1900, bookdecade1900, bookpubl, booksubjectaeronautics
