=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.