There wasn't. It was totally unlike taking a trip on earth, where the ever-varying scenery makes a journey pleasant. There was no landscape to greet the eye now. It was even unlike a trip in a balloon, for in that sort of air-craft, at least for a time, a glimpse of the earth can be had. Now there was nothing but a white blanket of mist to be seen, which rolled this way and that. Occasionally it was dispelled, and the full, golden sunlight bathed the projectile. The earth had long since dropped out of sight, for it required only a few seconds to put the _Annihilator_ high up in a position where even the most intrepid balloonist had never ventured. Mark and Jack sat for a few minutes in the pilot-house, looking out into the ether. But they soon tired of seeing absolutely nothing. "I wonder what we'll do when we get to the moon?" asked Jack of his chum. "Why, I suppose you'll make a dive for a hatful of diamonds, won't you? That is, if you still believe that Martian newspaper account." "I sure do." The boys found the two professors busy adjusting some of the delicate scientific instruments with which they expected to make observations on the trip, and after they reached the moon. "What is your opinion, Professor Roumann, of the temperature at the moon's surface?" asked Mr. Henderson. "I am in two minds about it," was the reply. "A few years ago, I see by an astronomy, Lord Rosse inferred from his observations that the temperature rose at its maximum (or about three days after full moon) far above that of boiling water." "Boiling water!" ejaculated Mark. "Wow! That won't be very nice. I don't want to be boiled like a lobster!" "Wait a moment," cautioned Mr. Roumann, with a smile. "Later, Lord Rosse's own investigations, and those of Langley, threw some doubts on this. There is said to be no air blanket about the moon, as there is about the earth, so that the moon loses heat as fast as it receives it; and it now seems more probable that the temperature never rises above the freezing point of water, just as is the case on our highest mountains." "That's better," came from Jack. "We can stand a low temperature more easily than we can to be boiled; eh, Jack?" "Sure. But I don't want to be frozen or boiled either, if I can help it. Guess I'll wear my fur suit that we brought back from the North Pole with us." "I agree with you, Professor Roumann, about the temperature," announced Mr. Henderson, "so we must make up our minds to shiver, rather than melt. But we are prepared for that." "What about there being no air on the moon?" asked Jack. "Oh, we can manufacture our own oxygen," said Mark. "We can walk around with an air tank on our shoulders, as we did when we went beneath the surface of the ocean. Now, I guess----"