CHAPTER I   MUMMY CAÑON

CHAPTER II   SOMETHING ABOUT DR. BYRD

CHAPTER III   A FALL FROM THE AIR

CHAPTER IV   THE WRECK AND THE AVIATOR

CHAPTER V   LOST!

CHAPTER VI   THE SCREAM IN THE WATERFALL

CHAPTER VII   A BADLY FRIGHTENED BOY

CHAPTER VIII   HAL’S DISCOVERY

CHAPTER IX   HAL A PRISONER

CHAPTER X   THE MYSTERY OF THE LEATHER BAG

CHAPTER XI   CONVINCING BAD.

CHAPTER XII   AIRSHIP PLANS

CHAPTER XIII   THE “PAINTER”

CHAPTER XIV   BUILDING THE AIRSHIP

CHAPTER XV   STOLEN WEALTH

CHAPTER XVI   FLIGHT

CHAPTER XVII   EXPLORING THE CAVE

CHAPTER XVIII   THE ISLAND IN THE AIR

CHAPTER XIX   THE RESCUING AIRSHIP

CHAPTER XX   THE PANTHER AND THE CAVE

CHAPTER XXI   TO FLATHEAD BY AIRSHIP AGAIN.

CHAPTER XXII   CLEARING HAL

CHAPTER XXIII   THE BOY SCOUTS OF THE AIR.

CHAPTER XXIV   MOUNTAIN LION BRIDGE