Early May found them a hundred miles toward their destination, and here, in one day, many interesting things happened. They had found their two slabs of whalebone, brought from the Arctic coast, of great value to them in trade. They had split one of these into small strips and peddled them out in barter to the men of the tribe, who coveted whalebone, and were as eager as stage Yankees for a trade. They had bought with this, among other things, two pair of rude snowshoes, and on the day I speak of, while the tribe rested, they started down river on an exploring trip. It was warm and bright, and thawed a little in the sun in sheltered nooks. The Kowak in its middle course winds among cliffs, carving its way through high bluffs on one side, leaving alluvial stretches of level flats at the base of other heights opposite. From one of these sheer bluffs, facing the south, wind and sun had taken the snow, and as they approached they saw sticking from the dark soil of its surface white objects like weather-worn logs of driftwood. “Funny!” said Joe; “they look like bones, those logs. See, there are some that look like the knuckle-bone of a ham, and there are others like rib-bones.” “Yes,” said Harry, taking up the simile, “and there are two that stick out of the frozen mud like an elephant’s tusks, only they are curved too much and about fifteen feet long. Let’s get nearer.” As they approached, their interest gave way to wonder. The seeming bones were bones in very truth, piled fantastically and protruding in strange profusion. Harry climbed by knobs and steps of bone part way up the bluff and shouted down to Joe. “These are tusks, mastodon tusks, sticking right out of the bank, and here is a bit of the skull sticking out with shreds of hide and hair on it. There must be a whole one frozen into the bluff here.” Joe climbed up and viewed the remains with him. It really seemed as if, concealed in the frozen mud behind the great tusks, the whole creature might be preserved, in cold storage as one might say, kept during the long centuries, and exposed by the crumbling of the bluff during the rush of the river torrent in spring. An astonishing number of bones were in this place, all of the mastodon, and the only explanation seemed to be that in the forgotten ages when the frozen zone was a warm one and the mastodon roamed there in large numbers, this ground must have been a deep bog, in which many of the creatures became mired and were in a great measure preserved, as peat preserves things. The boys settled it in this way to their own satisfaction, at least. “Come on,” cried Joe, in exuberance of spirits, “let’s ride the elephant.” “Ride the mastodon, you mean,” replied Harry; and each scrambled for a tusk. “Get up!” cried Harry, “cooning” along to the tip of his tusk. “Get up old fellow and give us a ride. Great Scott, he’s moving!”