Peter, wrapped in half a dozen blankets in addition to a leather flying-coat, was soon sound asleep in spite of the low temperature.
He had not slept for more than ten minutes when his uncle roused him.
"She's faltering—both engines," announced Uncle Brian laconically.
Peter rose stiffly to his feet. He had not the trained ear for mechanism that his uncle possessed, and as far as he could hear, the motors were still keeping up their rhythmic purr.
"Look at the gauge of the main fuel tank," suggested Uncle Brian.
His nephew picked up an electric torch and made his way to the 'midship compartment. He went sceptically enough, but on consulting the indicator, the state of the gauge fairly startled him. It stood at zero.
That meant that only one of the auxiliary tanks contained any kerosene, and owing to its position was useless unless the flying-boat was diving steeply or in an inverted position while "looping".
The tanks were three-quarters full when the flying-boat had passed out of Rioguayan control; and since only a few hours had elapsed, it was a matter of impossibility for the four motors even running all out to "mop up" anything like the quantity that had gone somewhere.
A hasty examination revealed the cause of the leakage. A drain-cock was half open, allowing a steady stream of kerosene to flow into space. At first thoughts, Peter attributed the leakage to the Rioguayan mechanic, until he remembered that the fellow had been locked up when left alone on board.
But there was little time for speculation.