"How do you know that?" asked Sam.

"Look at the white smoke!" answered Tommy. "I guess if you had made and answered as many Boy Scout smoke signals as I have, you'd know how to make a smudge."

"It's so bloomin' dark I couldn't tell whether the smoke is while or black!" declared Sam. "I can see only the bulk of it."

"If it was good and black," Tommy answered, "we couldn't see it so plainly. And, come to think about it," he added, laying a hand excitedly on Frank's shoulder, "there are two columns of smoke."

"I see the two now," Frank answered. "One column has just begun to show.

You know what that means, of course!"

"It means a Boy Scout signal for a.s.sistance," replied Tommy.

Doctor Pelton turned to the boys with an anxious face.

"Do you really mean that?" he asked.

"Sure we do!" replied Tommy. "Two columns of smoke ask for help."

"Then there must be Boy Scouts in trouble on the other side of the chasm!" the doctor concluded.

"That's about the size of it!" Frank exclaimed.

"Look here," Tommy declared, "we've just got to get across that crack! I wonder if it would be possible to find walls so slanting that we could pa.s.s down this side and up the other."

"Well, even if we did," Sam argued, "there's a rush of water at the bottom. I don't see how we could get across that."

"I know how we can get across it if we find the walls accommodating,"

Tommy exclaimed. "You saw how the trees tumbled into the chasm, didn't you? Well, if we can find a place where the moraine was heavily wooded, we'll find a bridge of tree trunks across any water there may be at the bottom! And the bridge may not be very far down, either!"

"Great head, little man!" laughed Frank.

"You ought to consider the matter very seriously before entering the chasm at all," suggested the doctor. "Remember that it is uncertain as to size and that the walls are liable to crumble."

"But see here," exclaimed Tommy, "there's a Boy Scout signal for help on the other side, and we've just got to get across! For all we know, the cabin may have been wrecked by the earthquake, and the boys may have been injured in some way!"

"I'm game to go!" shouted Sam.

"Of course I'll go with you," the doctor went on. "In fact, I am satisfied that you are doing the right thing in making the attempt to cross. I only uttered a warning which we must all heed whenever we come to a place where a crossing seems possible."

The boys soon discovered a place where the walls did not appear to be very steep and where the ma.s.s of trees which had fallen completely covered the bottom. Then, cautiously feeling their way, they crept down.

CHAPTER XVI

GEORGE AND SANDY CAUGHT

When George and Sandy left the cabin they saw the figure of the miner very dimly outlined away to the west.

"We ought to get closer," Sandy whispered. "First thing we know, he'll duck down into some hollow, and that'll be the last of him for the night. I guess we can creep up without his catching us at it."

"Of course we can!" replied George. "He's making so much noise himself that he can't hear us! He wouldn't make much of a Boy Scout when it came to stalking, would he?"

The boys succeeded in getting pretty close to the miner; so close in fact, that occasionally they heard him muttering to himself as he stumbled over rocks and occasionally became entangled in such underbrush as grew along the top of the moraine.

"We can't be very far away from the place where the bear tried to beat me up," Sandy whispered, as they drew up for a moment. "I wouldn't mind having a bite out of that same bear just about now!"

After a time they came to the head waters of the creek in which Will and Sandy had fished, and saw Cameron standing on the other side.

"He's going into the mountains!" whispered Sandy.

"That's exactly where he's keeping Bert," George agreed.

In a short time Cameron paused in his walk and uttered a low whistle.

"What do you think of that?" asked Sandy. "He's going to meet some one here. And that means," the boy went on, "that he's had a pal watching Bert while he's been away."

"And it also means," George added, "that we can't be very far from the spot where Bert is concealed. I hope so, anyway, for I'm about tired enough to crawl into my little nest in the cabin."

"I should think you'd talk about sleep!" scoffed Sandy. "You slept all the afternoon!"

"If you mention that long sleep of mine again," George said half-angrily, "I'll tip you over into the creek. I'm sore over that myself!"

While the boys stood waiting end listening an answering whistle came from the side of a mountain not far from the rivulet.

"There's his chum!" whispered Sandy. "If we get up nearer, we may be able to hear what they say."

The boys crept along under the dim light of the infrequent stars, and finally crouched down behind an angle of rock which was not more than twenty feet removed from where Cameron stood.

They had hardly taken their position when a second figure made its appearance. The two stood talking together in whispers for a short time and then started to walk away.

"There's something doing, all right!" exclaimed Sandy.

"Yes, indeed, there is!" agreed George. "They wouldn't come out into such a hole as this after midnight to tell each other what good fellows they are, or anything like that."

"I'm getting suspicious!" Sandy chuckled.

"Why suspicious?"

"Because those fellows whispered!"

"I see the point," replied George. "From our standpoint those fellows were all alone here in one of the wild places of Alaska, yet they drew close together and whispered when they communicated with each other!"

"They wouldn't do that," urged Tommy, "unless they were afraid of being overheard. It shows that they believe some one to be watching them."

The two men were now moving quite swiftly up the slope of the mountain.