After Tom had well explored the island, he told Frank they must build a fort. He had found the very spot for it, too, on a little hill. This was about a hundred feet high, and the top was hollow, like a cup, with only one opening into it. In fact, the top of the hill was part of the crater of an extinct volcano, and was shaped like the letter G, the doorway being only a gap in the rocks, through which no bear could squeeze.
Inside, the walls were twenty feet high all round, all bare rock; but the floor was covered with grass, and moss, and wild flowers.
Aralia and Pansy were wild with delight, and Pansy said she would now be able to sleep without ugly dreams.
Veevee would be her bed-fellow, and Floss would curl up with Sissie, and big Briton could sleep at the entrance.
So it was all arranged.
But as there could be no telling how long they might have to remain here, and as rain would be sure to fall, even if snow did not, Tom and Frank began to build a hut inside Fort Fairyland, as they called their strange abode.
Now each boy had—like all Greenland sailors—not only a large, many-bladed knife, with a saw in it, but a huge broad dagger in a leathern belt round his waist. So they did not want for tools.
They found the best wood for what they wanted growing close by the lake, in the shape of straight and strong willows. There were plenty of leaves, and grasses, and heath also.
It would be rather a long job, but they set to work with a will, and in three days' time they had dragged everything they wanted up to Fort Fairyland. The building of the hut was fine fun. At first it was only meant to be a kind of shelter on poles, but, as they had so much time upon their hands, they agreed to build real walls, and leave space for a door and a window. In little more than a week they had the framework all up, and the roof all made. It was thatched first with broad leaves, and then with grass. And, mind you a short ladder had to be made first to permit them to do the thatching. When this was finished, all the sides were filled in with willow branches, except door and window. Never a hole was left in it, for Aralia and Pansy collected heaps and heaps of dried moss, and the boys worked this in to fill up the gaps.