It was not more than half an hour later when Jess uttered a sharp cry of alarm. From the forward part of the aëroplane a wisp of smoke had suddenly curled upward. Like a blue serpent of vapor it dissolved in the air almost so quickly as to make Jess believe, for an instant, that she had been the victim of an hallucination.
But that it was no figment of the imagination was evidenced a few moments later by Peggy herself. Aroused by Jess's cry, she had made an inspection of the machine, with alarming results. What these were speedily became manifest.
"Jess! The machine is on fire!" she cried afrightedly.
As if in verification of her words there came a puff of flame and a strong reek of gasoline. It was just then that both girls recalled that the Golden Butterfly carried twenty-five gallons of gasoline, without counting the reserve supply.
Fire on an aëroplane is even more terrifying than a similar casualty on any other type of machine. Hardly had Peggy's words confirming the alarming news left her lips when there came a cry from Jess.
The girl had just glanced at the barograph. It showed that they were then 1,500 feet above the surface of the earth. The girl had hardly made this discovery before, from beneath the "bow" of the monoplane, came a wave of flame; driven from the steering wheel by the heat, Peggy drew back toward her companion. Her face was ashen white.
Left to itself the aëroplane "yawed" wildly, like a craft without a rudder. Then suddenly it dashed down toward the earth, smoke and flames leaping from its front part.
Both girls uttered a cry of terror as the aircraft fell like a stone hurled into space. Faster and faster it dashed earthward without a controlling hand to guide it. It was at this instant that Roy and Jimsy became aware of what had happened.
