“Now, what shall we do that we have got here?” she asked, as, after walking a few steps, he came to a stop.

“Wait, and see how things are coming out,” he answered.  “I begin to feel tired, so suppose we sit down and rest ourselves.”

The moment this was done, both uttered an exclamation of pleasure; for the relief from the distressing smoke was so great that it was as if they had emerged into the open country, where there was none of it at all.

“Why did we not think of this before?” said Nick; “we ought to have known that smoke doesn’t keep close to the ground.”

The atmosphere was not clear by any means, but the change was so marked that it appeared more than pure, and they sat several minutes gratefully inhaling that from which it seemed they had been shut off for many hours.

But their rejoicing was too soon; for, though it may be true that in a burning building the surest place in which to gain enough air to support life is close to the floor, yet there can be so much of the strangling vapor that it will penetrate everywhere.

Less than five minutes had passed, when a volume of smoke swept over and enveloped them, so dense that it was like the darkness of Egypt, that could be felt, and the suffering of the brother and sister was pitiful.

“Put your face close to the water,” called out Nick, as well as he could do from coughing and strangling.

At the same moment, their fevered cheeks touched the cold, refreshing surface, and something of relief was experienced.

“It won’t do to stay here,” said Nick, a moment later.

“But where can we go?”

“Out in the pond; there’s a better chance to breathe there than along shore.”

“But I can’t swim, Nick.”

“What of that?  I can, and I’ll take care of you; but there is plenty of wood and we can make a raft.  That reminds me that there was a raft here last week, when Sam Harper and I had a swim:  I wonder where it can be.  Help me to look for it.”

They moved slowly along the margin of the pond, peering through the gloom as best they could, but seeing nothing of the support on which they now placed so much hope.

Nick Ribsam, however, did not fail to notice one thing—­it was becoming hotter every minute and they could not wait much longer before entering the water in very self-defense.

They pushed bravely on, and when the circuit of Shark Pond was half completed, reached a point where the thick vapor lifted, or, more properly, it had not yet descended, and they stopped to rest themselves again.

“Well,” exclaimed Nick, with a sigh, “some folks would call this fun, but I don’t see where it comes in.”

“I don’t see how any one could find fun in such suffering; but, Nick, you will have to make a raft.”

“I believe you are right; there isn’t much chance to fasten these dry logs together, and I haven’t time to build one that will hold us both.”