When Leo had looked at all this bewildering beauty, Knops pushed open the mica door again, and they began to traverse the galleries of the rock cavern. He was surprised that none of the elves noticed him, nor even looked at him, and he asked Knops the reason. "I have rendered you invisible to them, my dear Leo, for two reasons: one is that you may be undisturbed in your examination of their work, and the other is that they may not be interrupted; for of course your presence would be a source of lively interest to them, and yet any stoppage of work would necessitate punishment." "Punishment?" repeated Leo, questioningly. "Oh yes; most of our hardest workers are elves of mischief and it is only by keeping them thus constantly employed that we prevent disorder. You have no idea what pranks they play." "And what is your authority among them?" asked Leo. "I am one of our King's cabinet; my title is Master Professor. My learning qualifies me to decide upon the plans of work, where to search for precious stones, and how best to prepare them for man's finding. Nothing is more amusing than the wonder and surprise men exhibit at what they consider their discoveries of minerals and gems, when for ages we have been arranging them for their clumsy hands." "How do you do this?" "Ah! it's a long story. Here you see the result of our long searches, and were it not for the processes we conduct none of these stones would ever be found. We can penetrate where man has never been; we can construct what man has in vain tried to do. Come with me to our diamond-room: we do not make many, preferring to find them; but as an interesting scientific experiment we have always liked to test our ability." So saying, Knops turned down a little lane lighted by what looked like small globes of white fire. "Electric light," said Knops, with a gesture of disdain, as he saw Leo blinking with wonder--"the commonest sort of a blaze; and yet men have nearly addled their brains over it, while we made it boil our kettles. It's the simplest and cheapest fuel one can have; but having utilized it so long, I am on the lookout for something new. Here, this is the way;" and again he opened a mica door. CHAPTER IV Blow-pipes and retorts, crucibles and jars, porcelain and glass vessels, of all odd sorts and shapes, confronted them on tables and shelves, and seated before small furnaces, with gauze protectors for their faces and metal ones for their knees, and queer little rubber gloves for their hands, were the very queerest of all the elves Leo had yet seen. They were thinner and much less muscular than the miners and stone-polishers, with eyes too large and legs too small for their bodies, so that they resembled nothing so much as spiders. "See how in the pursuit of the beautiful one can lose all beauty," said Knops, confidentially. "How hot it is here!" said Leo, gasping for breath.