Suddenly voices struck through the smother all about them. They seemed to come from below.
"It's thick as pea soup, captain!"
"Aye, aye; I'll be glad when we're out of it I kin tell yer. This bay's a bad place ter be in er fog."
"A ship," cried Jimsy. "Quick, Peggy," he almost yelled the next instant. "Set your rising levers."
The girl swiftly manipulated the machinery that sent the Golden Butterfly on an upward course.
But it was only just in time that this maneuver was carried out. All of them had a glimpse for an instant of the gilded ball on the main-mast head of the vessel beneath them. For an instant Peggy's watchful eye had been deflected from the height gauge, and she had allowed the Golden Butterfly to drop almost on the top of some coasting vessel's mast.
The danger over, they could not help laughing at the whimsical adventure.
"Just to think how utterly unconscious those fellows were of the fact that three human beings were hovering right above them and listening to every word of their conversation," chuckled Jimsy; "isn't it queer?"
A little while later a steamer's whistle boomed through the fog beneath them, but as the altitude register showed five hundred feet, they did not bother about it.
"At all events we know we're still above the water and not in danger of colliding with any church steeples," said Jess, and she found consolation in the thought.