"We're up about 2300," Andy answered, reading the register of their height.
Don again measured the angle between due north, as indicated by the compass, and their line of direction as shown by the longitudinal line of the plane. It showed that unconsciously in the dense blackness of the night they were again bearing inland.
A few brief words from the navigator, and there was a slight increase of speed, accompanied by a bank and outward turn, and then, as the mist on the glass-encased nacelle showed they were on the cloud line, a drop of a couple of hundred feet.
As they passed the rugged coast of Maine they could hear great waves pounding on the rocky shore, but it came up to them only dimly against the throbbing of their engines and the soothing song of the resistless propellers.
Dawn found them above a coast line which none of them knew. It was bleak and barren, with no evidences of population upon it.
"Just as I reckoned," said Don, easily. "The wind got behind us stronger than we knew. We've more than covered our destination. We're heading for Labrador, and, at this rate, the North Pole."
The navigator was right. They banked and turned, and in three hours came within sight of welcome Halifax.
They made an easy descent and rolled their machine onto the portable skids to take it into the hangar.
But so easily and logically had Big Jack explained their apparent purpose in being away that there was nothing more than an ordinary curiosity about them on their return.