“What is it?” cried the boy.

For answer Mr. Henderson pointed to the needle.  It was almost straight up and down.

“Well?” asked Jack, who did not understand much about scientific things.

“That means we are almost at the north pole!” cried the professor.  “At the exact north the needle points straight down, because the pole is a magnet, and being directly underneath pulls the end of the needle down.  See, it is almost down now.  I believe we shall really get to the pole, and my ambition will be realized.”

Aside from the wound Andy had received, none of the party was any the worse for their adventures as prisoners.  Now that they were safe back on the ship they were inclined to laugh at the fears they had felt.

For several hours the Monarch was held to her course at a fairly good speed.  Then, at the professor’s order, the engines were turned on at full power, since the air was still, and there was no sign of a storm.  Straight to the north the craft shot, every one on board now anxious, as they became aware that they were near to their destination.

The former life was resumed, and the hours of watch were marked out as they had been.  The sun still shone, never setting, but by this time the adventurers were used to perpetual day.  Dirola kept to herself, not saying a word to anybody.

“I think I’ll drop the ship down a bit and see what sort of a country is beneath us,” announced Mr. Henderson about four o’clock, though whether it was four o’clock in the morning or the afternoon, no one knew.  However, it did not matter much.  “If there is an open sea around the north pole, as some believe,” he went on, “we ought to see some signs of it now.”

He let some gas out of the bag, and the Monarch slowly settled toward the earth.  The inventor opened the trap door that covered the plate glass in the floor of the cabin, and peered down.  When within five hundred feet of the ground he signaled to stop the descent of the ship.

“Nothing but ice, ice, ice!” he announced.  “Big hills and mountains of it.  There is no sign of open water.  Well, we are not quite at the pole yet.”

Jack’s turn at the wheel came to a close, and Mark relieved him.  Washington, who had been on duty pretty steadily in the engine room, gave his place up to the inventor, and stretched out to sleep.  Bill and Tom were snoring in their bunks, and Andy was resting easily, the pain from his wound being relieved by some ointment the professor put on.

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.