CHAPTER I The Occurrence of the Impossible CHAPTER II Steel Becomes Interested CHAPTER III Seaton Solves the Problem of Power CHAPTER IV Steel Liberates Energy—Unexpectedly MYSTERIOUS EXPLOSION! CHAPTER V Direct Action CHAPTER VI The Object-Compass at Work CHAPTER VII The Trial Voyage CHAPTER VIII Indirect Action CHAPTER IX Lost In Space CHAPTER X The Rescue CHAPTER XI Through Space Into the Carboniferous CHAPTER XII The Mastery of Mind Over Matter CHAPTER XIII Nalboon of Mardonale CHAPTER XIV. Nalboon Unmasked CHAPTER XV. The Escape from Mardonale CHAPTER XVI. An Osnomian Marriage CHAPTER XVII. Bird, Beast, or Fish? CHAPTER XVIII The Invasion CHAPTER XIX The Return to Earth