"I'm out fer dat money dis trip," put in Danny. "Say, I hopes yer git about a million dollars, so I do!" and he shook his head enthusiastically.
"Don't speak of it quite so loudly, Danny," cautioned the Englishman. "This is a secret search, you know."
"Yes, dat's so—I forgot," answered the Irish lad. "I'll be as mum as an oyster after dis."
Coming to a bit of high ground overlooking one of the numerous valleys of upper Porto Rico, they sat down on several flat rocks to rest.
Robert Menden calculated that they were within a few miles of Caguas, and announced that the next night might be spent there.
"And then we must pick up some reliable native guide to take us to the great caves," he added.
The scenery from where they sat was truly grand. Hills and valleys were clothed in every variety of tropical growth, from the tallest of royal palms to the heavy grass—grass the like of which none of the boys had ever seen. Far in the distance were the great mountains, ranging along for miles, their sharp ridges clearly defined against the blue sky. Smaller ridges came down toward them, the lower ones more smooth on their tops, and covered with great patches of grass, where fed cattle and sheep innumerable.
"It's certainly a charming island, so far as looks go," murmured Leander. "But I believe this atmosphere would make the most active man in the world lazy sooner or later."
"It's a good climate for invalids," said Robert Menden. "Some day Porto Rico is bound to become a great winter resort for Americans and others."
"I want to get to the top of yonder mountains before I leave," put in Leander. "If we—Great Scott! Look out!"