In the middle of this room stood the flying ice ship.

The vessel was made of an extremely light, bullet-proof material called aluminum, and looked like a two-masted schooner, with a rounded, wedge-shaped bow and stern.

At the truck of each mast was a large gyroscope, while upon the upper part of each of the yards many more of these wheels were arranged in a horizontal position to lift the engine in the air.

Upon the yards and stays were furled sails, to be used while traveling before the wind.

At the bow was a long bowsprit, a searchlight at its foot, and upon its deck, in the forward section, a pilot-house.

There were three big steel ice runners on each side, and between them two spiked wheels for propelling the boat over the ice without sails.

At the stern was an ice rudder, above it a water rudder, a water screw, and on the end of a shaft an immense air-wheel for propulsion.

Bull’s-eyes broke the sides of the hull to admit light into the interior.

As they stood looking at the boat, which was operated by electricity, the door-bell rang, and Frank saw the professor start nervously, turn very pale, and glare at the entrance.

“What’s the matter? You look nervous!” said Frank.