"This," said quick-eyed Marjory, pointing northwestward, when the explorers had returned for the third time to the sunny clearing, "is the widest trail of all."

"For my part," said Mr. Black, "I don't know why there should be any trails here at all. No one has lived here for four years. Sometimes fishermen come here in gasoline launches for a few days in the spring, or hunters for a week or two in the fall, but never in sufficient numbers to make as marked a trail as this—we must certainly investigate this one."

This wider trail led them for perhaps a hundred feet through a dense thicket of shrubbery; then, with a suddenness that was startling, the explorers found themselves in another clearing, about half the size of the first. In it stood a curious structure with a rounded top. It was built of bent strips of wood, covered with large sheets of rough birch bark, bound in place with willow withes, and sewed in spots with buckskin thongs. It was blackened with age and smoke.

"It looks," said Henrietta, "like the top half of a big balloon. And mercy! How horrible it smells."

"What is it?" asked Mabel. "Is it a bear's den? Ugh! I hope Mr. Bear isn't home."

"It's a birch-bark wigwam," replied Mr. Black, "and somebody has occupied it recently. See the bed in the corner?"

Sure enough, there was a bed—some balsam boughs covered with a dingy blanket and some rags that had once been a quilt. On an upturned box was a burlap bag containing potatoes and a few perfectly sound onions. A deer-skin was stretched to dry against one rounded side of the wigwam and just opposite the doorway of the queer hut were a number of blackened stones, evidently a rude fireplace. Hanging against a convenient tree-trunk were some sooty and most uninviting cooking utensils; a camp kettle, a frying-pan, a lard pail or two, a big iron pot, a long-handled spoon.

"It isn't a great while," said Mr. Black, frowning perplexedly, "since these things were used. But who, I'd like to know, used them?"

"Wild Indians," offered Marjory, glancing fearfully over her shoulder.

"Pirates," shuddered Mabel.