“Take it all in all,” said Barney to Bruce some time later, “I think our trip promises to be dangerous enough to satisfy even a bloodthirsty young savage from the Canadian army.”

“Or a young Cherokee from the wilds of Boston Commons,” laughed Bruce, heaving a wrench in the general direction of his companion.

But, though they went about their work in a playful mood, they did it with great care.  After they had taken the two little Timmies for several rides, they declared the airship quite ready for further voyaging.  “And as for gasoline,” said Bruce, “we still have two hundred and forty gallons in the tank which will give us a-plenty for the trip, and several hours to spare; but coming back—­that’s another matter.”

Barney realized that this was, indeed, another matter, and, though he shared the Major’s hope of securing a supply at the trading station, his face grew grave at thought of being stranded more than a thousand miles from civilization at the beginning of winter, and with only a few days’ supply of provisions.  What if this trading station was one of those myths that float down from the North?  Or, what if it had been abandoned?

Barney shook himself free from these thoughts, and seizing his mandolin, went to join Bruce and Timmie on saxophone and rudely-devised Indian kettledrums in a wild-woods symphony, while the children danced wild steps the boys had never seen.

* * * * *

“Well, we’re off!” Barney said this, as he buckled on his harness and touched the starting lever.  The wheels of the starting gear bumped over the thin-crusted snow and jolted through Timmie’s wheat stubble, then the great bird began to rise.

Winter had set in.  Now they glided over dark forests of spruce, and now swept above great stretches of barren lands.  The air was biting cold.  They were thankful enough for their face-protectors, their electric hand and foot warmers, their fur-lined leather union-alls.  But best of all was the glorious freedom of it.  Soaring on and on over untrodden wildernesses, with no thought of dangers known and unknown, made them feel like explorers of a new world.  The engines worked in perfect harmony.  A gentle breeze from the south urged them on their way.  The sun soon set and a long night began, but what of that?  The moon and snow lighted the earth as if by day, and with a silvery glory.  And now the Northern Lights began to flicker, flash and shoot across the sky.

Now they passed over a wide expanse of white, which they knew to be Dismal Lake.  This was frozen over; then surely Great Bear Lake, two hundred miles farther north, would be frozen, too.  Their safe landing would be assured.