94 OUR PHYSICAL WORLD 



warping movements of the plane. When a gust of wind tended 

 to throw up one wing, the front edge of that wing was turned 

 down while the front edge of the opposite wing was turned up. 

 As the wings cut the air in this new position, the machine regained 

 its balance. 



Anyone who has undertaken to ride a bicycle will appreciate 

 in some measure the difficulties encountered in learning to balance 

 the aeroplane. In balancing the bicycle one has only to avoid 

 falls to right or left. If you tend to tip over to the right you 

 turn the front wheel to the right and so bring the line of support 

 of the two wheels underneath your center of gravity. In the 

 aeroplane, however, you are not riding on the solid ground but 

 in unstable air. You are likely to be buffeted by the winds that 

 blow up and down as well as by cross-currents that come from 

 right or left. The Wrights, however, became very skilful in 

 flying their gliders, and then they attached a gasoline engine 

 to drive such a glider. This engine operated two propellers 

 by means of chains. They launched their machine from an 

 inclined rail, a rather bungling contrivance for getting under way ; 

 but in December, 1903, they made their first successful flight. 

 This was made in an out-of-the-way place in South Carolina. 

 After demonstrating to their own satisfaction that they could 

 really fly, the machine was packed away while they were getting 

 patents on their various devices. 



French inventors were also busy in building and perfecting 

 aeroplanes. Santos-Dumont, after becoming somewhat skilful 

 with the glider, undertook flights with an aeroplane which was 

 constructed for him by the Voisin brothers. This was in 1906. 

 In November of that year he made a flight of some 230 yards. 

 He did not follow up his success, however, but abandoned this 

 machine and undertook the construction of an aeroplane which 

 should rise from the water. In 1907 another Frenchman who 

 later became famous in air work, Henri Farman, began practice 

 with a Voisin machine and before the end of the year made a 

 flight of nearly half a mile. Another French aviator who was 



