Jack and Mark build an airship and head North, hoping to find a rare plant that grows only in Alaska. But a freak earthquake causes a chunk of the Earth, along with our protagonists, to fly into outer space.
e of "leap-frog" through the air.
The professor had himself constructed many wonderful machines for transportation through the air, under the ground, and both on and beneath the sea; and in them he and his young comrades had voyaged afar.
Narrated in the first volume of this series, entitled, "Through the Air to the North Pole," was the bringing together of the two boys and the professor,--how the scientist and Washington White rescued Jack and Mark after a train wreck, took them to the professor's workshop, and made the lads his special care. In that workshop was built the Electric Monarch, in which flying ship the party actually passed over that point far beyond the Arctic Circle where the needle of the compass indicates the North Pole.
Later, in the submarine boat, the Porpoise, the professor, with his young assistants and others, voyaged under the sea to the South Pole, the details of which voyage are related in the second volume of the series, entitled "Under the Oc