“Out of the earth,” smiled Norris. “Up through hot springs, geysers and volcanoes. The water vapor was always here, you know,—mixed with the molten rock and gases.”
“I swan!” ejaculated the old guide. “I thought I knew something about rocks, but—this beats anything in my kid’s fairy books.”
“You bet!” Ace agreed. “You just wait till you hear––”
“I expect we’d better start on now,” Norris rose. “Do you chaps realize what a predicament we are in?” and shading his eyes with a lowered hat brim, he peered off across the hummocky granite slopes, which shone mirror-like in places under the noon-day sun.
A moving speck in the sky to the North drew an exclamation from him. In another moment a sound that increased to a hum like that of a giant motor-boat descended from the skies, and the speck disclosed itself as a mammoth aeroplane.
“Signal them!” cried Norris. “What can we signal them with? Get out your pocket mirrors, quick!”
CHAPTER IV
WITH THE AIR PATROL
“Signal them!” chorused the three boys, acting on Norris’s suggestion, (flashing their distress with their pocket mirrors), while Long Lester stood measuring the flight of the aeroplane.