214. Other Inventions in the War. The "depth bomb" was an out and out new invention. 11 could be "dropped" over the spot where a submarine was seen. Very often it blew the submarine to pieces.
The "tank" was a "moving iron fort" drawn by a tractor. It could tear wire entanglements to pieces and cross enemy trenches. The "depth bomb" and "tank" were used mainly by the Allies.
The wide use of "poison gas" was first introduced by the Germans. Guns able to shoot many miles were invented. One of them carried seventy miles or more.
SUGGESTIONS INTENDED TO HELP THE PUPIL
The Leading Facts. 1. Edison learned telegraphy, and made his own instruments. 2. Edison saved the day in Wall Street, and made his reputation, as well as plenty of money. 3. He made many telegraph and telephone inventions. 4. He built great laboratories in New Jersey, where many men worked helping him. 5. Edison invented the phonograph, and worked to improve the electric light. 6. An argument about horseracing led to the invention of moving pictures. 7. Edison improved the moving picture camera. 8. C. Francis Jenkins invented the first complete moving picture machine. 9. During the World War remarkable moving pictures were taken on all fronts. 10. Moving pictures are often used in schools and elsewhere for educational purposes. 11. The typewriter was really the work of many different inventors. 12. Typing machines for the blind first invented. 13. Christopher Sholes' typewriter was the first practical one invented. 14. The dictaphone is really a development of Edison's phonograph. 15. It consists of two machines, and is used in business offices to save time. 16. Steam automobiles were the first kind invented. 17. For one hundred years many inventors worked trying to build automobiles. 18. The first gasoline automobile in this country was built by Charles Duryea. 19. The United States is far in the lead in the number of automobiles manufactured and used. 20. Men have for ages tried to discover a way to fly. 21. They filled balloons with gas or heated air which carried them far up. 22. Dirigible balloons were invented by Zeppelin. 23. Wilbur and Orville Wright built a successful heavier-than-air machine. 24. The gasoline engine made their success possible. 25. Airplanes can now go three miles a minute. 26. All the great progress in flying has come since Wright's first successful flight in 1903. 27. In the war airplanes were used for observing the enemy, for fighting, and for bombing. 28. In this country airplanes are now used chiefly for carrying mail. 29. A hydroplane has a boat-like body. 30. In 1919 three successful flights were made across the Atlantic. 31. John P. Holland was the first to succeed in building a submarine. 32. The submarine is guided by means of the periscope, and is valuable in peace and war. 33. Depth bombs and tanks were new inventions. 34. The Germans introduced poison gas.
Study Questions. 1. What books could Edison read at twelve? 2. Tell of his thousand newspapers. 3. What were the cause and the effect of his first lessons in telegraphy? 4. What was his first great invention? 5. What did he find in Wall Street, New York? 6. How much did Edison think of asking for his invention? 7. How much was offered him? 8. Tell the story of the work in Edison's shop at Newark, New Jersey, 9. Why did he want a great library at Menlo Park? 10. How does sound travel? 11. What was the trouble with Edison's first phonograph? 12. Name some of the uses of the phonograph. 13. Make a list of Edison's great inventions. 14. Tell how the first moving pictures came to be made? 15. How did the machine Edison invented differ from a real moving picture machine? 16. Who invented the first complete moving picture machine? 17. How important is the moving picture business? 18. Tell some incidents of the war which you saw in moving pictures. 19. Does your school use a moving picture machine in its classroom work? 20. How are lessons studied when moving pictures are used? 21. Where can schools get their films? 22. Name two other uses for moving pictures. 23. What earlier invention resembled the typewriter? 24. Name one simple thing the lack of which kept men from inventing a typewriter sooner. 25. Describe Sholes' first typewriter. 26. From what invention did the dictaphone come? 27. How is dictating done by means of the dictaphone? 28. What difficulty held back the progress of the automobile? 29. Name two ways in which this has been overcome. 30. How old is the automobile business? 31. How does the United States compare with other countries in number of automobiles used? 32. How did auto trucks keep the Germans from capturing Paris? 33. What is a Zeppelin or dirigible? 34. Tell about the studies of the Wright brothers. 35. What progress had others made before the Wright brothers succeeded? 36. What was unusual about Wilbur Wright's flight in 1903? 37. What is a monoplane? a biplane? a hydroplane? an airship? 38. Name some peace-time and war-time uses of airplanes. 39. Tell the story of Holland's inventions. 40. What are the uses of the submarine? 41. Name the first submarine to cross the Atlantic.
Suggested Readings. Thomas A. Edison: Mowry, American Inventions and Inventors, 85-89; Dickson, Life and Inventions of Edison, 4-153, 280-388.
Christopher L. Sholes: Hubert, Inventors, 161-163.
The Automobile: Doubleday, Stories of Inventors, 69-84; Forman, Stories of Useful Inventions, 161-163.
Wilbur and Orville Wright: Wade, The Light Bringers, 112-141; Delacombe, The Boys' Book of Airships; Simonds, All about Airships; Holland, Historic Inventions, 273-295.