"Because there has been a working here. Some one must have dug down and thrown out all that mass of broken rock. Part has been washed away; but all this, you see, though worn and rounded by the waves washing it about, has been dug out of the rock." He had walked to a long slope of wave-worn fragments of rock as he spoke, forming a steep ascent that ran up into a rift in the great cliff; and he drew Dick's attention to the fact that what seemed like a level place a hundred feet above was so situated that anything thrown down would have fallen in the niche or combe of the cliff just beyond them. "Now, my fine fellow," said Mr Temple, as he picked up a piece of wave-polished stone, "what's that?" "Serpentine," said Will quietly. "And this?" said Mr Temple. "Granite, sir." "Eight; and this?" "Gneiss," replied Will. "Quite correct. Now this," he continued, breaking a piece of stone in two with his hammer. "Cop--no, only mundic," cried Will, who had nearly been caught tripping. "Right again. Now this?" He picked up a reddish piece of stone which, when broken, showed bright clear crystals, and close to the ruddy stone a number of little black grains. "Tin," cried Will eagerly; "and a rich piece." "Let me look at the tin," cried Arthur eagerly; and the piece being handed to him, "where?" he cried; "there's no tin here." "Tin ore, my boy," said Mr Temple quietly. "Those black grains are rich tin." "Well, I shouldn't have thought that," said Arthur; "and I should have thought that was gold or brass." "Then you would have thought wrong," said Mr Temple sharply. "All is not gold that glitters, my boy; and you can't find brass in the earth. What can you find, my lad?" he continued, turning sharply to Will. "Copper, sir, and tin and zinc." "Then what is brass?" said Mr Temple. "Copper and zinc mixed." "Not copper and tin?" "Copper and tin, sir, make fine bronze, same as the ancient people used to hammer for swords and spears; but I can't understand, sir, why two soft metals like copper and tin should make a hard one when they are mixed." "And I cannot explain it to you," said Mr Temple smiling. "Are we going to stop here long?" said Arthur impatiently. "Oh? don't go yet," cried Dick, laughing; "I want to hear Will say his miner's catechism." "Oh! very well," said Mr Temple, smiling. "What is mundic, then, my lad?" "A mussy me! as if every lad here didn't know what mundic was!" cried Josh to himself; but he spoke loud enough for the others to hear. "Well, what is mundic, then?" said Mr Temple quickly to Josh. "What's mundic?" growled Josh, picking up a yellow metallic-looking piece of rock; "why, that is, and that is, and that is. There's tons of it everywhere." "To be sure there is, my man; but what is it?" said Mr Temple. "Well, ain't I showing of you!" growled Josh. "This here's mundic." "The gentleman means what is it made of?" whispered Will, and then he added two or three words.