"Upon my word, Dick!" cried Arthur. "I believe you have made a discovery! I believe that it is the line of an old ditch, after all; though the pack-trains doubtless used it as a convenient road as far as the top of the cañon and then switched off down here by that shelf in the wall."
"That's my idea," said Dick, nodding his head.
"But, look here, Dick," Arthur went on, after a moment's thoughtful pause. "Suppose it is an old ditch—where did the water come from? That's the question. A ditch without water isn't much use."
Dick laughed. "No," said he. "I understand that well enough. The water came from this 'island,' up here above our heads, and was carried across the cañon in a flume!"
"Ah!" I cried. "I see! What we at first supposed to have been a bridge up there, built for the accommodation of the pack-trains, was in reality a flume for carrying water."
"That's what I believe," replied Dick.
"Well, but see here, Dick," remarked Arthur again. "Suppose that there was a flume there for carrying water—where's the water now? That's the point. That's what I want to know."
"Ah!" replied my partner. "And that was what I wanted to know, too. That was the very question that bothered me until I talked to Pedro about it just now. I asked him if he had ever seen or heard of a stream of water coming down from the top of this high land, and I can tell you he eased my mind of a load when he told me he had. He says there is a good big waterfall which jumps off the cliff on the north side of the 'island' and falls into this stream we are camped upon now, but about twelve or thirteen miles below this point, following the bends of the creek."
"Is that so? Then the chances are that that is the stream from which the Pueblos used to get their water. Did you ask Pedro if he knew of any way of getting up there?"