CONTENTS
| CHAPTER | PAGE | |
| I. | “Nobly Rewarded!” | [1] |
| II. | Just in Time | [10] |
| III. | A New Friend | [17] |
| IV. | The “Sybilline” Whistle | [29] |
| V. | Four Hundred Dollars | [37] |
| VI. | The Airship Idea | [45] |
| VII. | Mystery | [53] |
| VIII. | At the Aero Meet | [60] |
| IX. | A Bomb-dropping Event | [67] |
| X. | A Rush Order | [74] |
| XI. | The Dart | [82] |
| XII. | A Serious Charge | [88] |
| XIII. | The Man in the Gig | [96] |
| XIV. | The Mysterious Pin | [102] |
| XV. | A Mean Enemy | [108] |
| XVI. | Stealing an Invention | [115] |
| XVII. | On Time | [121] |
| XVIII. | The Five Hundred Dollar Prize | [128] |
| XIX. | “Go!” | [135] |
| XX. | Crusoes of the Air | [144] |
| XXI. | A Fight with a Bear | [151] |
| XXII. | A Friend in Need | [157] |
| XXIII. | The Lost Aviator | [163] |
| XXIV. | Homeward Bound | [170] |
| XXV. | Conclusion | [191] |