PART III

I EARLY EXPERIMENTS WITH HEAVIER-THAN-AIR MACHINES 77 II FIRST PRINCIPLES OF AN AIRPLANE 91 III THE PIONEERS 99 IV THE AIRPLANE IN THE WORLD WAR 128 V SOME OF THE PROBLEMS THE INVENTORS HAD TO SOLVE 150 VI FAMOUS ALLIED AIRPLANES 170 VII GERMAN AIRPLANES IN THE WORLD WAR 189 VIII HEROES OF THE AIR 205 IX THE BIRTH OF AN AIRPLANE 223 X THE TRAINING OF AN AVIATOR 232 XI THE FUTURE STORY OF THE AIR 244 READING LIST 256 INDEX 259

LIST OF ILLUSTRATIONS

Seaplanes NC-1, NC-3 and NC-4 of the U. S. Navy starting the trans-Atlantic flight from Rockaway. The NC-4 on its victorious trans-Atlantic flight, sixty miles at sea _Frontispiece_

FACING PAGE Montgolfier experiment at Versailles, 1783 10 The first cross-channel trip 11 Diagram showing the main features of the spherical balloon 16 Cocking's parachute 30 A German Zeppelin 31 Inflating a service balloon on the field 40 Army balloon ready to ascend 41 Giffard's airship 54 Santos-Dumont rounding the Eiffel Tower 55 Baldwin U. S. "Dirigible No. 1" 66 The British Army "Baby" dirigible 67 Cross section of the gas bag of the _Astra-Torres_, showing method of car suspension 70 "The Blimp," C-1, the largest dirigible of the American Navy 72 The balloon of the _U. S. S. Oklahoma_ 73 Diagram showing the essential parts of an airplane 95 Wright starting with passenger 98 An early Farman machine prior to start 99 Wright machine rising just after leaving the rail 114 An early Wright machine, showing its method of starting from a rail 114 The propeller department in one of the great Curtiss factories 115 A photograph of northern France taken at a height of three thousand feet 138 An airplane view of the city of Rheims, showing the cathedral 139 Diagram of an internal combustion engine cylinder, showing principle on which it works 157 This photograph shows the relative size of the giant Caproni bombing plane and the French baby Nieuport, used as a speed scout 170 The Spad, the pride of the French air fleet 171 A Handley-Page machine tuning up for a flight 182 The launching of a Langley, a giant bombing airplane 183 Side view of a Sopwith triplane 187 An American built Caproni airplane 188 This Curtiss triplane has a speed of one hundred and sixty miles an hour 189 A giant Gotha bombing plane brought down by the French 198 German Fokker plane captured by the French 199 Captain Eddie Rickenbacker 218 The first bag of mail carried by the U. S. Aero Mail Service 219 A photograph made ten thousand feet in the air, showing machines in "V" formation at bombing practise 242 A group of De Havilland planes at Bolling Field near Washington 243