The boy in the conning tower kept his eye on the two compasses, the one telling the direction, the other the nearness to the north pole. The latter gradually kept inclining more and more toward the earth.
"If we can only make it," thought Mark. "It will be something no one has ever done before. My! What a story the papers would make of it if they knew!"
"How is she running?" asked the captain, coming into the tower.
"Very well, indeed, sir."
"You might send her up a little," suggested the professor. "Keep her about half a mile high, and I'll be with you again before long."
The professor went to his bunk, and Mark was pleased enough to be left alone in charge of the ship. He held the wheel firmly, and did not deviate half a point from the northern course.
He had been steering for half an hour when he was suddenly aware of a dense gloom that settled down all about him. Then there came a great roaring sound. The air craft rocked violently. The wind whistled shrilly through the cordage and careened the Monarch to one side.
Then the whole atmosphere grew from a dense black to a strange opaque whiteness: a whiteness that shut out the view from every side, and enveloped the ship as if it had fallen into a feather bed. Mark started back in fright and let go his hold on the steering wheel.