They were not cold, for their fur garments kept them comfortably warm, and there was no wind to make the freezing temperature search through the crevices of their clothing. But it was the desolate silence, the utter absence of any form of life save the pale green vegetation that got on their nerves. It was like being in a dead world--on a planet that seemed about to dissolve into space. They began their further search for the projectile with hope in their hearts, but this gradually gave way to despair as they wandered on over the desolate surface, and saw nothing but the same rugged peaks, the same yawning caverns and the innumerable craters, large and small. On they wandered, looking on all sides for the missing projectile, but they had no glimpse of it. Even climbing to one of the high peaks, whence they had a view of the surrounding country, afforded them no trace of the _Annihilator_, They were utterly lost. Old Andy, who, by reason of his experience as a trapper and hunter, had taken the lead, came to a halt. He looked around helplessly. He did not know what to do. "Well, boys," he remarked at length, "I don't like to say it, but I can't seem to get anywhere. I give up." "Give up?" murmured Jack, in blank dismay. "Yes, for the time being," said the old man. "I'm all played out. I guess we all are. We must have a rest. Here's a sort of cave. Let's crawl in and have a sleep. Then maybe we can do something to-morrow--no, not to-morrow, for they don't have that on the moon, where the day is fourteen days long--but after we sleep we may be able to find our way back. Anyhow, I've got to get some sleep," and without another word the old hunter went into the cave, and, fixing his life-torch near his head, where the fumes from it would dissipate the poisonous gases of the moon, he closed his eyes, and was soon in slumber. "I--I guess we'd better do the same," said Jack, and Mark nodded. They were both sick at heart. CHAPTER XXV THE PETRIFIED CITY For a time, after they had entered the cave, which was in the side of a rugged mountain, the boys talked in low tones of their perilous situation. For that it was perilous they both knew. Had they been on the earth, lost in some desolate part of it, away from civilization, their plight, would have been bad enough with what little food they possessed. But on the far-off moon--the dead moon, which contained no living creatures save themselves, as far as they could tell--with no form of animal life that might serve to keep them from starving, with only the scantiest of vegetation, their situation was most deplorable. "And then there's another thing," said Mark, as if he was cataloguing a list of their troubles. "What is it?" asked Jack. "I guess we have all the troubles that belong to us, and more, too." "Well, what are we going to do when the life-torches give out, and we can't breathe any more?" asked Mark dubiously.