“I supposed such must be the case,” Thorwald continued. “And now, when you consider the great age of Mars, perhaps you will not be surprised to learn that this new matter, coming to us from the outside, was sufficient to increase the weight of our globe and gradually decrease the rate of speed at which we were traveling through space.” “I am surprised, though,” said the doctor, “because the accumulation of meteorolites on the surface of the earth is so exceedingly slow that it would take millions of years, at the present rate, to increase its diameter one inch.” “But perhaps they came much faster in past ages. Let me ask you, Doctor, if it is not a fact that the rate of revolution of Mars around the sun is slower than the earth’s? I suppose you are far enough advanced in astronomical science to answer that.” “Yes,” replied the doctor, “you are correct. I believe the earth speeds along at nineteen miles a second, while Mars travels only sixteen miles in the same time.” “We know by our computations that our speed is much less than it once was, and our theory is that this has in some way hushed those terrible storms and winds which we know were formerly so frequent.” Here the doctor thought he saw a chance to make a point, and spoke as follows: “If the meteorites come in quantities sufficient to have caused such changes, it seems to me their fall must be as great a menace to your peace as the evils they have cured. They do not strike the earth in large numbers, but still we have a record of a shower of meteoric stones which devastated a whole village. I suppose all parts of your globe are by this time well populated, and how can you be entirely free from trouble when you are living in constant danger of the downfall of these great masses of rock?” “But we don’t have meteorites now,” replied Thorwald. “Oh, you don’t?” “No, they ceased falling long ago. Mars is going slow enough for the present.” “Very kind of them, I am sure, to stop when you didn’t need them any longer,” said the doctor; “and I suppose you have some plausible reason to give for their disappearance.” “Yes, we believe that the interplanetary space was well filled with these small bodies, circling around the sun, and when their multitudinous and eccentric orbits intercepted the orbits of the planets, they came within the attraction of these larger masses. Mars has merely, in the course of time, cleared for itself a broad path in its yearly journey and is now encountering no more straggling fragments.” “There, Doctor,” said I, “you are well answered. And now, Thorwald, tell us how you have escaped other evils, famine and fire for instance.”