We must try all we can to avoid being on the island when the ice breaks up, and we must make for the mainland as soon as ever the sea is frozen over."

Hobson was right. It would take about three months to build a thirty or thirty-five ton vessel, and the sea would not be open when it was finished. It would be very dangerous to embark the whole party when the ice was breaking up all round, and he would be well out of his difficulties if he could get across the ice to firm ground before the next thaw set in. This was why Hobson thought a boat a forlorn hope, a desperate makeshift, and every one agreed with him.

Secrecy was once more promised, for it was felt that Hobson was the best judge of the matter, and a few minutes later the five conspirators were seated together in the large room of Fort Hope, which was then deserted, eagerly examining an excellent map of the oceanic and atmospheric currents of the Arctic Ocean, special attention being naturally given to that part of the Polar Sea between Cape Bathurst and Behring Strait.

Two principal currents divide the dangerous latitudes comprehended between the Polar Circle and the imperfectly known zone, called the North-West Passage since McClure's daring discovery-at least only two have been hitherto noticed by marine surveyors.

One is called the Kamtchatka Current. It takes its rise in the offing outside the peninsula of that name, follows the coast of Asia, and passes through Behring Strait, touching Cape East, a promontory of Siberia. After running due north for about six hundred miles from the strait, it turns suddenly to the east, pretty nearly following the same parallel as McClure's Passage, and probably doing much to keep that communication open for a few mouths in the warm season.

The other current, called Behring Current, flows just the other way. After running from east to west at about a hundred miles at the most from the coast, it comes into collision, so to speak, with the Kamtchatka Current at the opening of the strait, and turning to the south approaches the shores of Russian America, crosses Behring Sea, and finally breaks on the kind of circular dam formed by the Aleutian Islands.

Hobson's map gave a very exact summary of the most recent nautical observations, so that it could be relied on.

The Lieutenant examined it carefully before speaking, and then pressing his hand to his head, as if oppressed by some sad presentiment, he observed-

"Let us hope that fate will not take us to remote northern latitudes. Our wandering island would run a risk of never returning."

"Why, Lieutenant?" broke in Mrs Barnett.

"Why, madam?" replied Hobson; "look well at this part of the Arctic Ocean, and you will readily understand why. Two currents, both dangerous for us, run opposite ways. When they meet, the island must necessarily become stationary, and that at a great distance from any land. At that point it will have to remain for the winter, and when the next thaw sets in, it will either follow the Kamtchatka Current to the deserted regions of the north-west, or it will float down with the Behring Current to be swallowed up by the Pacific Ocean."

"That will not happen, Lieutenant," said Madge in a tone of earnest conviction; "God would never permit that."

"I can't make out," said Mrs Barnett, "whereabouts in the Polar Sea we are at this moment; for I see but one current from the offing of Cape Bathurst which bears directly to the north-west, and that is the dangerous Kamtchatka Current. Are you not afraid that it has us in its fatal embrace, and is carrying us with it to the shores of North Georgia?"

"I think not," replied Hobson, after a moment's reflection.

"Why not?"

"Because it is a very rapid current, madam; and if we had been following it for three months, we should have had some land in sight by this time, and there is none, absolutely none!"

"Where, then, do you suppose we are?" inquired Mrs Barnett.

"Most likely between the Kamtchatka Current and the coast, perhaps in some vast eddy unmarked upon the map."

"That cannot be, Lieutenant," replied Mrs Barnett, quickly.