What is on Mars? "I only wish you _would_ come along with me," replied the doctor. "I have no idea what intelligent, educated person I can persuade to accompany me, unless he is given an interest in the discoveries. You are the person most interested in the enterprise, and you should go. If it is money-making that detains you here, you may rest assured that we shall find fortunes for both of us somewhere." "I am a slave to the excitement of my business," I answered. "I could not possibly spend two or three months in a lonely cell, flying through space, without a ticker or a quotation of the market. Besides, there are people on the earth I should not care to leave, unless I was certain of getting back soon." "You may be sure of excitement enough, and of a continuously novel kind. Besides, of what interest are the people of this earth, who are all alike, and whom we have known all our lives, compared with the rapture of finding a new and different race, of investigating another civilization, and exploring an entire new world?" "I shall have to warn my friends about you and have myself watched, lest you persuade me and run away with me when the time comes. If your adventures are half as exciting and varied as your theories, I should hate to miss them. But tell me why you have chosen Mars for a first visit." "Because of all the planets he is the one which most resembles the Earth in all the essential conditions of life. He is the Earth's little brother, situated next farther out in the path from the Sun. He has the same seasons, day and night of the same length, and zones of about the same extent. He possesses air, water, and sufficient heat to make habitation by us quite possible. Moreover, his gravity problem will not put earthly visitors at a disadvantage, as it would on the very large planets, but rather at a distinct advantage over the Martians." "What do you expect to find on Mars?" I queried. "That is a very comprehensive question, and any answer is the merest guess-work, guided by a few known facts," replied the doctor. "The principal controlling fact is the reduced gravitational attraction of Mars, which will make things weigh about one-third as much as on the Earth. The air will be far less dense than here. In the mineral kingdom the dense metals will be very rare. I doubt if platinum will be found at all; gold and silver very little; iron, lead, and copper will be comparatively scarce, while aluminium may be the common and useful metal. Gases should abound, and doubtless many entirely new to us will be there. It is not unlikely that many of these will serve as foods for the animals and intelligent beings. It is also quite possible that the heavier gases may run in channels, like rivers, and be alive with winged fish and chameleons." "How about vegetation?" I suggested.