em," said Peter. "Having only one
trap gives us a slim chance. But suppose we do get them, what then?"

"Why, we'll have to have some sort of cage ready in which to carry
them; then we'll make all the speed we can back to Toronto," replied
Horace.

"And give up the diamond hunt?" cried Mac, in disappointment.

"What else can we do, anyhow?" replied Horace. "The flour is almost
gone and we're almost barefoot. And see here, boys," he went on,
earnestly, "I hate to admit it, but I'm afraid my calculations were
wrong on these diamond-beds. I thought it all out while I was coming
home from Whitefish River. Somewhere up here in the North there must
be a place where those diamonds came from--but I'm beginning to believe
it isn't in this part of the country. You see, the geological
formation is all different from the kind where diamond matrix is ever
found. Those stones I picked up may have been traveling for a thousand
years down one creek and another. They may have come down in the
glacial drift. I was altogether too hasty, I see now, in assuming that
they originated in one of the rivers where I found them.

"They may have come from a river a hundred miles away. Or perhaps from
deep underground. We should have made a study of the geological
structure of this whole North Country, the direction of the glacial
drift, and everything. Then we should have come in here prepared to
travel a thousand miles and stay all summer, or for two summers, if
necessary."

"Hanged if I'll give it up," said Mac stubbornly. "However," he added,
"we must certainly try to catch these black diamonds, and we can keep
on prospecting at the same time."

They uncached their outfit, pitched the tent again, and prepared
supper; meanwhile they talked of the foxes until they reached a high
pitch of enthusiasm. Even Mac admitted that the black foxes bade fair
to be as profitable as a small diamond-bed would be. As for Fred, it
was almost with relief that he let the diamond hunt take second place
in his mind. The continual strain of labor and failure had robbed the
search for the blue clay of much of its fascination.

Early the next morning they paddled up the river to the point where
Mac's blazed trail came down to the shore, and set out to reconnoiter
the den. After half an hour's tramping across the woods they reached
the rocky ridge; through the field-glass they scrutinized the lair,
which was about two hundred yards away.

Not