Waking some hours after he had first fallen asleep, the man of science had indulged his sleepless moments by plunging into mental calculations of an abstruse character. He was deeply engrossed in these, when the sudden sound had broken in on the quietness of the night.

“Bless me, I could have sworn that I heard a footstep, and a stealthy one, too,” muttered the professor to himself, “I must be getting nervous. Possibly that is what made me wake up, and—wow!”

The ruminations of Professor Wintergreen broke off abruptly as he suddenly felt something warm and hairy brush his face.

“It’s a bear!” he yelled, springing to his feet with a shout that instantly aroused the others,—Jack Merrill, the rancher’s son; Ralph Stetson, his schoolmate from old Stonefell; Coyote Pete, and Walt Phelps.

“A b’ar!” yelled Coyote Pete, awake in a flash, “wha’r is ther varmint?” As he spoke, the plainsman drew forth his well-worn old forty-four and began flourishing it about.

Before the others could say a word a dark form bolted suddenly through the camp, scattering, as it went, the embers of the dying campfire.

“It’s a bear, sure enough!” exclaimed Ralph, as the creature, a small bear of the black variety, howled and stumbled amidst the hot coals.

All at once its shaggy coat burst into flame, and with a cry of intense agony it dashed off into the woods.

“Poor creature!” cried Jack Merrill, “it will die in misery unless it’s put out of its agony quickly. Pete, lend me your gun.”

The plainsman handed it over with a quick interrogation to which he received no reply. Instead, Jack made a swift dash for the spot, a few feet distant, in which the horses of the party were tethered. Throwing himself on the back of one, with a twisted halter for a bridle, he set off in hot pursuit of the unfortunate bear.