“We have neither,” answered my visitor, “nor do we require them, for reasons easily explained. There are two conditions of our planet which render the navigation of the air entirely safe and successful. They are the greater density of our atmosphere, and the diminished force of gravity compared with yours. Our air ships, as you would call them, are easily made to sustain and move large cargoes, by vacuum chambers and electric motors. Our inventors have long since surmounted the difficulties of adverse wind currents, and these vessels, of both public and private use, may be seen constantly moving about in all directions, and at all altitudes, with but few serious accidents. “There are no large oceans like yours on Mars, and our rivers are so small as not to serve the purposes of commerce. You will perceive, then, that our facilities for navigating the air were bestowed upon us as a means of transportation, in lieu of the convenient waterways which you enjoy. As you may anticipate, from the small size of our rivers, there are no extensive mountainous water sheds upon our surface. Instead of your immense, desolate, and storm-beaten seas, we have a series of lakes, everywhere varying in size, but none of them larger than seventy-five of your miles long, and forty broad. “The relative density between water and an animal body being such on our planet as to render the possibility of drowning by accident impossible, the fear and horror existing with you of involuntary immersion in the depths is entirely unknown. Our numerous lakes are therefore scenes of the most enjoyable, and what would be with you, reckless diversion. The upsetting of a boat with its load of excursionists, no matter where, results in merely a harmless frolic. The human body there sinks in the water only a little above its middle, and we have contrived, by web-like fastenings to the hands and feet, a means of propulsion so rapid as to nearly equal our speediest locomotion on the land. During our long summers, when the temperature of the water is agreeable, lake journeys, especially by the young, are among the most popular amusements. This, to you, strange condition of density is productive of a state of affairs partaking of the humorous, although leading to much domestic perplexity and annoyance. Our children take to the water in the summer season as naturally as your water fowl, and the loss of offspring upon the lakes, at that tender age which precludes their knowledge of the return direction, is the source of an immense amount of parental disturbance and worry. The straying of children upon the waters is attended, however, with but little danger; since, if by any possibility they remain undiscovered during the night, they can, owing to the buoyancy of their bodies, sleep tranquilly and delightfully upon their backs, resting upon the cushions of the waters until rescued, as they are sure to be on the succeeding day, by one of the numerous airships constantly skimming the