Serge was right in his conjecture. What appeared to be the river-bank was merely a curtain of tough, closely compacted Alaskan moss, closely resembling peat in its structure, one foot thick, and reaching from the crest of an overhanging bank to the edge of the river. It had thus held together, and fallen to its present position when the river undermined and swept away the earth from beneath it. That it presented a sloping surface instead of hanging perpendicular was owing to a great number of timbers, the ends of which projected from the excavated bank behind it. Serge had broken through the moss curtain, fallen between these timbers to the beach, and then cut his way out. Now, as he suggested, what better camping-place could they ask than the warm, dry, moss-enclosed space from which he had just emerged.
"I never saw nor heard of anything so particularly and awfully jolly in all my life," pronounced Phil, after the three travellers had entered this unique cavern, and started a fire by which they were enabled to see something of its strange interior. "And, I say, Serge, what a thoughtful scheme it was on your part to provide a chimney for the fire before you lighted it! See how the smoke draws up? If it wasn't for that hole in the roof I am afraid we should be driven out of here in short order. But, hello, old man! Whew—w! what are you throwing bones on the fire for? It reminds me of your brimstone-and-feather experiment on Oonimak."
"Bones!" repeated Serge in surprise. "Are those bones? I thought they were dry sticks."
"I should say they were bones!" cried Phil, snatching a couple of the offending objects from the fire. "And, sure as I live, this log I am sitting on is a bone too. Why, it's bigger than I am. It begins to look as though this place were some sort of a tomb. But there's plenty of wood. Let's throw on some more and light up."
"Toughest wood to cut I ever see," growled Jalap Coombs, who was hacking away at another half-buried log. "'Pears to be brittle, though, and splits easy," he added, dodging a sliver that broke off and flew by his head.
"Hold on!" cried Phil, picking up the sliver. "You'll ruin the axe. That's another bone you're chopping. This place is a regular giants' cemetery."
CHAPTER XXVI.
CAMPING 'MID PREHISTORIC BONES.
So strange and uncanny was the place in which our sledge party thus unexpectedly found themselves, that Phil was for exploring it, and attempting to determine its true character at once; but practical Serge persuaded him to wait until they had performed their regular evening duties, and eaten supper. "After that," he said, "we can explore all night if we choose."
So Phil turned his attention to the dogs, which he unharnessed and fed, while Serge prepared supper, and Jalap Coombs gathered a supply of firewood from the bleached timber ends projecting from the bank behind them. He tested each of these before cutting into it to make certain that it was not a bone, quantities of which were mingled with the timber.