Knops touched a spring and set a new series of wheels in motion, when, instantly, a gushing fountain flowed up in a small stone basin beneath a rustic cross; then a little lake appeared, on which were sailing small swans; and finally a rushing, roaring flood started some mill-wheels and almost threatened destruction to the tiny buildings upon its banks. "This," said Knops, "shows you how we use the power of our reservoirs, but it can give you no idea of the immense trouble we have in laying pipes for great distances. Some of our elves find it so difficult that they beg for other work, and many run off altogether and live above-ground, inhabiting the regions of springs and brooks, and so muddying them and filling them up with weeds that men let them alone, which is just what they desire." "Do fish ever clog your pipes?" asked Leo. "Never. We have none in our lakes; the water is too pure and free from vegetable matter for fish. It is doubly distilled. Taste it." Leo took the glass which Knops offered, and confessed he had never tasted anything more delicious. "We sometimes force carbonic gas into mineral springs, but that, as well as the salts considered so beneficial, is left to our chemists to regulate. Paz, do you know anything about this?" "Not much, Master Knops. I have seen iron in various forms introduced, but think that is usually controlled by the earth's formation." Leo sighed at his own ignorance, and vowed to study up these matters; but Knops, seeing his look of dejection, asked, "How would you like a bath?" "Delightful. Where? Surely not in the lake; it looks so cold and glassy I should not dare." "Oh, no, no," laughed Knops. "Do you think I'd let you bathe in a reservoir? Never! We are too cleanly for that, begging your pardon. Here is our general bath. It's quite a tub, isn't it?" "I should think so," said Leo, surveying quite a spacious apartment, about which were pipes and faucets, clothes-lines and screens. Here his friend left him, and he was glad to doff his garments for a plunge. He found that he could make the water hot or cold at will, and so luxurious was it that he would have stayed in any length of time had not a crowd of elves come chattering in, and with whoop and scream surrounded him. Though they could not see him, they were conscious of some disturbing force in the water, and in an instant a lot of them had scrambled on his back, and were making a boat of him. They pulled his hair and his ears unmercifully, and because he swam slowly, with their weight upon him, they whacked and thumped him like little pirates. But he had his revenge, for with one turn he tumbled them all off, and sprang from the bath, leaving them to squirm and squabble by themselves. Laughing heartily at their antics, he rejoined Knops and Paz, whom he found poring over some maps spread out before them.