There was a faint creaking of the car again, and soon the doctor said, "Pull away!" I threw all my force into the effort and gave a tremendous heave, and tumbled over backwards. Had I not done so, the projectile must have hit me as it glided rapidly from the car, sinking very slowly to the sand about fifty feet away. I scrambled to my feet, went in front again, and easily dragged it along on the sand to an open place just beyond the trees. There the doctor allowed it to settle. It sank into the loose sand about eight inches, remaining steady in this position. "She works beautifully!" I cried. "How I would like to see her turned loose for a real flight!" "That will come to-morrow night," said the doctor, crawling out of the port-hole. "But if you will help me remove these boxes from the experimental model, you shall see it lost in the sky." We uncovered and dragged out a small steel thing, about the same shape as the projectile, but less than a foot thick and four feet long. It had a lid opening into its batteries from the top. The doctor entered his compartment to secure some chemicals. "If you have no further use for this model," I suggested, "why not create a very strong current and let it sail off into indefinite space?" "Very well; I don't wish to leave it behind me for some one to discover, and I can't take it along. We will send it off for a long trip, and if it falls back it will be into the lake." "Wait a moment, then! Let's put a good-bye message in it;" and so saying I took an old envelope from my pocket and wrote on the back of it with a pencil in a bold hand: "Farewell to Earth for ever!" Laughing, I put this inside and closed the lid. Then the doctor turned down a thumb-screw upon a little wire which connected the poles, and stepped back quickly. Presently the forward end began to rise slowly, until it stood upright, but there it hesitated. The doctor stepped forward and gave the thumb-screw a hard turn down, and the model lifted immediately, rising at first gradually, but soon shooting off with the whizz of a rocket over the lake. We watched it as long as we could distinguish its dark outline. "It will go a long way," said the doctor. "I have never seen it make so good a start. It will lose itself in the lake far from here." We fastened up the front window and the port-hole, and started back to Whiting, where the doctor was to remain all night, so as to begin work early in the morning. Presently, as we walked along, the doctor said,-- "Well, Isidor, now you have seen a practical demonstration of the elementary working of the projectile. You also have some idea of all there is to be discovered up yonder in the red planet. You are the most interested in making and profiting by those discoveries. I want you to consent to go along." "Haven't you secured a companion, then?" I inquired.