“Yes, natural,” said the Doctor, carefully scanning the sides of the place with a small glass. “Originally natural, but this place has been worked.”
“Worked? What, dug out?” said Bart. “Why, what for—to get water?”
“No,” said the Doctor, quietly; “to get silver. This has been a great mine.”
“But who would have dug it?” said Bart, eagerly. “The Indians would not.”
“The people who roughly made the zigzag way up to the top here, my boy.”
“But what people would they be, sir? The Spaniards?”
“No, Bart. I should say this was dug by people who lived long before the Spaniards, perhaps thousands of years. It might have been done by the ancient peoples of Mexico or those who built the great temples of Central America and Yucatan—those places so old that there is no tradition of the time when they were made. One thing is evident, that we have come upon a silver region that was known to the ancients.”
“Well, I am disappointed,” cried Bart. “I thought, sir, that we had made quite a new find.”
“So did I at first, Bart,” replied the Doctor; “but at any rate, save to obtain a few scraps, the place has not been touched, I should say, for centuries; and even if this mine has been pretty nearly exhausted, there is ample down below there in the canyon, while this mount must be our fortress and our place for furnaces and stores.”
They descended cautiously for about a couple of hundred feet, sufficiently far for the Doctor to chip a little at the walls, and find in one or two places veins that ran right into the solid mountain, and quite sufficient to give ample employment to all the men without touching the great lode in the crack of the canyon side; and this being so, they climbed back to meet Joses, who had been just about to descend after them.