"A projectile," said Mr. Roumann again. "I have studied it all out, and I think the projectile, shaped somewhat like a great shell, such as they use in warfare, or, more properly speaking, built like a cigar or a torpedo, is the only feasible means of reaching Mars. We shall go in a projectile, two hundred feet long, and ten feet in diameter at the largest point. That will offer the least resistance to the atmosphere of the earth, though when we get within the atmosphere of Mars, and are subjected to its attraction of gravitation, we shall meet with even less resistance." "Why?" asked Jack, who wanted to know the reason for everything. "Because," answered Mr. Roumann, "from my observations I have proved that the atmosphere of Mars is much less dense than is that surrounding the earth, and the attraction of gravitation there is about two-thirds less. That is, an object that weighs one hundred pounds on the earth will weigh only thirty-three pounds on Mars." "That's the stuff!" cried Jack. "Why?" asked Mr. Roumann in some surprise. "Then I'll have a chance to lose weight," replied Jack. "I'm getting too fat here. I weigh a hundred and eighty pounds, and that's too much for a lad of my age. When I get to Mars I'll only weigh--let's see, two-thirds of one hundred and eighty--" and Jack got out pencil and paper and began figuring. "It's sixty pounds!" exclaimed Mark, who was quick at figures. "How are we to get to Mars, Mr. Roumann?" demanded Jack. "I will tell you," answered the blue-eyed man. "When you and the professor have constructed the projectile, after plans which I shall draw, I will apply my new, wonderful, secret power, and--" "If yo' gen'men will kindly project yo'se'ves hitherward, an' proceed to discuss de similitodinariness ob de interplanetary conjunction what am waitin' fo' yo' heah, de obverseness of de inner constitutions will be expeditiously relieved," spoke the colored man, suddenly looking in the room. "Does that mean supper is ready, Washington?" asked Professor Henderson. "Yes, sah. It suah do." "Then why didn't you say so?" "I did, perfesser." "Well, perhaps you thought so. Washington has a very peculiar habit of using big words, just because they sound so imposing," went on the professor. "He spends all his spare time consulting the dictionary." "I have noticed it," remarked Mr. Roumann, smiling. "Well, suppose we go out to supper?" went on Mr. Henderson. "You boys must be hungry." "I can eat," admitted Jack. "You'll get stouter if you do," warned Mark with a smile. "Can't help it. Wait until we get to Mars." "Oh, yes, you didn't finish telling us how we were to get there, Mr. Roumann," said Jack. "I'll tell you while we're at supper," said the scientist. "I confess that Washington's announcement came just at the right time. I am very hungry." CHAPTER V THE SECRET POWER