"Mark thinks so, but I don't!" cried Jack, enthusiastically. "Look here, Professor Henderson, and also Mr. Roumann. Here is one of the newspapers that we brought back with us in our projectile, the _Annihilator_, after our trip to Mars. I have been translating some of the articles in it, and to-night I came across one that told of a trip made by some of the inhabitants of Mars to the moon, in a sort of projectile, like ours, only more on the design of an aeroplane. "They landed on the moon, the article states, and found a big field, or deposit, of Reonaris, which I claim are diamonds. Mark says I'm wrong, but, Professor Henderson, isn't Reonaris to the Martians what diamonds are to us?" "It certainly is," agreed the older scientist, and he looked for confirmation to his scholarly companion. "Reonaris is substantially a diamond," said Professor Roumann. "It has the same chemical constitution, and also the diamond's hardness and brilliancy. But I don't understand how any diamonds can be on the moon." "You can read this for yourself," suggested Jack, passing over the paper, which was one of some souvenirs brought back from what was the longest journey on record, ever taken by human beings. Mr. Roumann adjusted his glasses, and carefully read the article that was printed in such strange characters. As he perused it, he nodded his head thoughtfully from time to time. Then he passed the paper to Professor Henderson. The older scientist was somewhat longer in going over the article, but when he had finished, he looked at the two boys, and said: "Jack is right! This is an account of a trip made to the moon by some of the Martians, who have advanced much further in the art of air navigation than have we. Some of the words I am not altogether familiar with, but in the main, that is what the paper states." "And doesn't it tell about them finding a field of Reonaris?" asked Jack eagerly, for he was anxious to prove to his chum that he was right. "Yes, it does," replied Mr. Henderson. "And Reonaris is diamonds, isn't it?" asked Jack. "It is," answered Professor Roumann gravely. "Then," cried Jack, "what's to hinder us from going to the moon, and getting some of those diamonds? The Martians must have left some! Let's go to the moon and get them! We can do it in the projectile with which we made the journey to Mars. Let's start for the moon!" For a moment there was silence in the laboratory of the scientist. It was broken by Washington White, who remarked: "Good land a' massy! Annodder ob dem trips through de air! Well, I ain't goin' to no moon--no sah!! Ef I went dere, I'd suah get looney, an' I has troubles enough now wid'out dat, I suah has!" And, shaking his head dubiously, the colored man shuffled from the room. CHAPTER II SOMETHING ABOUT OUR HEROES