AIRSHIPS AND AIRPLANES 317 



ing two months 1200 passengers were carried across the 

 Channel. 



SUPPLEMENTARY QUESTIONS FOR CLASS DISCUSSION 



1. Which seems to have greater possibilities for the future, 

 the airship or the airplane ? 



2. How does the airman control his airplane? 



3. How are airplanes kept from tipping? 



REFERENCES 



Cressey, Discoveries and Inventions of the Twentieth Century, 



E. P. Button Co., New York City. Chap. 16. 

 Darrow, The Boys' Own Book of Great Inventions, Macmillan Co., 



New York City. Chaps. 8-9. 

 Delacombe, Boys' Book of Airships, F. A. Stokes Co., New York 



City. 

 Johnson, Modern Inventions, F. A. Stokes Co., New York City. 



Chaps. 3, 4, 6, 7. 

 Maule, Boys'. Book of New Inventions, Grosset and Dunlap, 



New York City. Chaps. 1-3. 

 Navigating the Air, by the Aero Club, Doubleday Page and Co., 



New York City. 



