Professor Featherwit chuckled softly while at work, but neither he nor Bruno made reply in words. And then, his arrangements perfected save for closing the circuit, which could only be done after all hands had entered the air-ship, he spoke to the point: “Come, boys. You've had a rough bit of experience this day, and there may be still further trouble in store, here in this unknown land. Better make sure of a full night's rest, and thus have a reserve fund to draw upon in case of need.” There was plenty of sound common sense in this adjuration, and, only taking time to procure a can of fresh water from yonder stream, the two youngsters stepped within that charmed circle, permitting their uncle to close the circuit, and then test the queer contrivance to make sure all was working nicely. A confused sound broke forth, resembling the faraway tooting of tin horns, which blended inharmoniously with the ringing of nearer bells, all producing a noise which was warranted to arouse the heaviest sleeper from his soundest slumber. “That will give fair warning in case any intruder drifts this way,” declared the professor, chucklingly, then sinking down and wrapping himself up in a close-woven blanket, similar to those employed by the boys. “Even a ghost, or a goblin, do you reckon, uncle Phaeton?” “Should such attempt to intrude, yes. Go to sleep, you young rascal!” But that proved to be far more readily spoken than lived up to. Not but that the brothers were weary, jaded, and sore of muscle enough to make even the thought of slumber agreeable; but their recent experience had been so thrilling, so nerve-straining, so far apart from the ordinary routine of life, that hours passed ere either lad could fairly lose himself in sleep. Still, when unconsciousness did steal over their weary brains, it proved to be all the more complete, and after that neither Bruno nor Waldo stirred hand or foot until, well after the dawn of a new day, Professor Featherwit shook first one and then the other, crying shrilly: “Turn out, youngsters! A new day, and plenty of work to be done!” CHAPTER VII. THE PROFESSOR'S GREAT ANTICIPATIONS. A stretch and a yawn, which in Waldo's case ended in a prolonged howl, which would not have disgraced either of their four-footed visitors of the past evening, then the brothers Gillespie sprung forth from the flying-machine, entering upon a race for the brawling mountain stream, “shedding” their garments as they ran. “First man in!” cried Bruno, whose clothes seemed to slip off the more readily; but Waldo was not to be outdone so easily, and, reckless of the consequences, he plunged into the eddying pool, with fully half of his daylight rig still in place. The water proved to be considerably deeper than either brother had anticipated, and Waldo vanished from sight for a few seconds, then reappearing with lusty puff and splutter, shaking the pearly drops from his close-clipped curls, while ranting: