going wrong, and I imagine I'm getting a poor supply of gas. Take a look at the tank, will you, and see if it's all right!"
At that Jack ceased to chuckle. He realized from what the other said that he meant it seriously. Accordingly Jack bestirred himself to carry out the instructions of the pilot, which he was best able to do from his position aft.
A brief interval of silence followed, save for the constant hum of the machinery and the whirling propellers. Then Jack uttered a loud cry that expressed both astonishment and alarm.
"Tom, you guessed it!" he called. "The blooming tank is empty, and we're feeding on the scant reserve in the smaller tank!"
"Try to find out if a bullet cut a hole in the tank, and let our juice run out!" Tom now ordered.
Jack had already started an examination on his own account, and he almost immediately announced a finding.
"Just what happened, Tom!" came his cry, in a tone of dismay mingled with disgust. "Why, there are two holes, one far above the other! I reckon it came from below, after all. But the tank is empty, and only for that automatic feed change, meant for such an emergency, we'd have been running on hot air before now."
"There's not enough petrol in the small tank
