Part 22 (1/2)

[Ill.u.s.tration: ”_The old man pointed to the rocky wall_” [See p. 152]]

”I might add,” continued John, ”that when the courses are not regular it is called _broken_ ashlar; when stones of less than one foot in breadth are used it is called _small_ ashlar; if the wall is backed by rubble, or inferior work it is called _b.a.s.t.a.r.d_ ashlar. Then every kind of surface has a particular name, like the _random-tooled_, where the tool marks are shown in all directions; _rusticated_ when only the joined edges are trimmed up; _prison-rustic_ when it is pitted with deep holes; _herring-bone_ when it is tooled in rows of opposite directions to each other; and _nigged_ when finished up with a pointed hammer.”

Within an hour the stones were removed and put aside, and then Ephraim was treated to another surprise when he was made acquainted with the little electric flash lights which John exhibited. With these they entered the cave.

All savage tribes have some sort of animals, as pets, and dogs are the most frequent. This was the case among these people. The dogs were with the party, and, as usual, ahead of the procession. Two of them went ahead on a scouting expedition, while John and the boys, with their flash lights followed.

After they had gone, probably two hundred feet, there was a slight descent apparent in the floor of the cave, and ahead were the two dogs stretched out, lifeless.

George ran ahead, as he noticed them, and John shouted out: ”Do not touch them!”

He stopped, and looked back, and then slowly walked up to the animals.

John requested the party to halt, and he went forward, and put his foot on one of the dogs. ”We must go back,” he said.

”Are they dead?” asked Harry, as he came forward.

”Why not take them out and see what the trouble is?” inquired Harry.

”No need for that,” responded John. ”I know what the trouble is.”

”Is there any danger in the cave?”

”Yes.”

Ephraim and the natives were now alarmed. It will be remembered that the universal belief among the natives is, that to go into these caves unbidden, means death. True, John had shown the fallacy of this on several occasions, but here was positive evidence that death had visited the dogs, and this might be the fate of those who attempted to go on.

But the most alarming thing was the fact that John himself was the one who said there was danger, and that they must return. He did not venture to make an explanation until they were out of the cave.

”There is carbonic acid in the cave, and as it is a deadly poison we cannot go in until it is removed.”

”That seems singular,” responded George. ”I went in as far as the dogs, and it didn't affect me.”

”But you did not reach down to touch the dog.”

”I saw you touch the dog, and it didn't seem to affect you.”

”I touched it with my feet and not with my hands.”

”I cannot see what difference that makes.”

”If you had touched the dog with your hands it would have brought your face down near the floor of the cave, and the gas is at the bottom of the cave only.”

”Why should it be there and not all over?”

”Because it is much heavier than the air we breathe, and remains at the bottom, just like water. If you recall, this part is lower than the corridor through which we came, so that it could not run out. I have always observed that in all the other caves the floors within were higher than the entrance, and in such cases there is no liability of getting poisonous gases.”

”But how are we to make the investigation, under the circ.u.mstances?”

”We must remove the gas.”