Amongst other difficulties the story-writer here meets with, by no means the least confronts him when he is called upon to decide which of various theories put forward by different scientists he shall adopt as a starting-point. Mars, for instance, may have an atmosphere which is like ours, or one that is either thinner or denser, or it may have no atmosphere at all. As to this nothing is known with certainty, and the most learned authorities differ one from another. In these circumstances, I have adopted the supposition which seems best suited to my story—namely, that the air there may be denser than it is on the surface of our globe; but I do not wish to be understood as asserting it as a fact. The same remark applies to the assumption that diamonds or other precious stones do not exist naturally in Mars. In regard to these two points, I have felt it may be allowable, as children say, to ’make believe’ a little in forming a groundwork upon which to build up a story. As to the rest, I have refrained, in deference to the known prejudices of young people, from interjecting constant scientific explanations in the course of the narrative. Only sufficient has been introduced here and there to justify the hope that none will sit down to its perusal without getting up a little the wiser. We are all of us, as Sir Isaac Newton so aptly yet reverently expressed it, ’only as children picking up pebbles on the seashore while the great ocean of knowledge lies stretched out before us.’ I shall be well satisfied if, in addition to affording pleasure to youthful readers, I enable them to pick up incidentally even so much as a few grains of the sand which lies beside the pebbles upon that wondrous, glorious shore. THE AUTHOR. *CONTENTS.* CHAPTER I. THE FALL OF THE GREAT METEORITE II. WHAT GERALD SAW III. STRANGE VISITORS IV. GERALD CARRIED OFF V. KING IVANTA VI. THE KING’S OFFER VII. OFF ON A TRIP TO MARS VIII. A NARROW ESCAPE IX. ARMEATH’S SECRET X. CAPTURED BY A COMET XI. ’WELCOME TO MARS!’ XII. PRINCE ALONDRA XIII. THE PALACE IN THE CLOUDS XIV. TOM CLINCH’S STATEMENT XV. HUNTING THE GREAT MARS EAGLE XVI. IN DIRE PERIL XVII. LESSONS IN FLYING XVIII. A ROYAL PROGRESS XIX. A DARING PLOT XX. THE DEATH POOL XXI. A SECRET TREASURE-HOUSE XXII. MALTO XXIII. A FOUL DEN XXIV. AT THE PAVILION XXV. AGRANDO THROWS OFF THE MASK XXVI. THE WIRELESS MESSAGE XXVII. A DESPERATE VENTURE XXVIII. SAILING ON THE STORM-WIND XXIX. ATTACKED IN THE DARK XXX. CAPTURED XXXI. AT HOME IN A VOLCANO XXXII. IVANTA A FUGITIVE XXXIII. A QUEER HUNT XXXIV. A NIGHT EXPEDITION XXXV. HOW IVANTA GAINED A FLEET XXXVI. THE OLD WELL XXXVII. THE FIGHT FOR THE STRONGHOLD XXXVIII. A GREAT AERIAL BATTLE XXXIX. THE END OF THE STRUGGLE XL. CONCLUSION *LIST OF ILLUSTRATIONS.*