"I know they do, but still I stick to my idea," Frank went on.
"And this promises to be an extra strong outburst. Nick said so anyhow; didn't he, Frank?" Bob queried, a new anxiety in his tone.
"Just what he did. You're wondering now, that if what I said is true, whether this passage right here is one of those through which all that water dashes, on its way to the rocky barranca?"
"Yes, that's the truth. How about it? Could you see any signs here to tell about that?"
"I suppose I could if they were here, but I don't discover any. Besides, I thought of that before we entered, and I give you my word that I don't believe any big volume of water ever went out through here. It couldn't do it and not leave some sign behind."
Bob heaved a big sigh.
"Well, I'm right glad to hear you say that, Frank, seeing that we're so far in now, we wouldn't have any chance to escape if it came along. Whew! I wouldn't like being carried through here, and shot out of the muzzle like a bullet. But seems to me the place is getting bigger right along, Frank."
"Just what it is. Now you can see how like the neck of a bottle the cave is; and I think that has had a heap to do with the way that thunder noise gets loose. Why, they say that some days, or nights, it can be heard more than twelve miles away. I've seen Navajo Injuns drop flat on their faces, and lie there all the time we could hear the distant thunder in a clear sky over our way."
"But is it possible that some hermit is living in this cave?" asked Bob, thinking that it must be a queer sort of person who would remain where he must listen to such fearful sounds every once in a while.
"I told you to notice when we heard the noise the first time," Frank went on; "while we were in camp on the plain, that the night was clear, and the wind almost in the Southeast. Well, I made sure that it was in exactly the same quarter tonight when we were climbing the mountain. That means something, Bob."