"

All the time they had been talking, Knops had been leading the way
through long passages and down steep steps, of which Leo's long legs had
to compass several at a stride.

Now they came to a low tunnel through which Leo had to creep for what
seemed to him miles. Strange to say, the weariness which so often
compelled him to rest or doze seemed to be leaving him. He felt an
altogether new impulse, a desire to explore these recesses, and a great
respect for Knops's learning also made him desirous of conversation,
which was something he had always avoided by answering questions in the
shortest possible way.

The tunnel was not only long and low, but it was dripping with moisture,
and the air oppressive with what seemed to be steam. Leo heard wheezing
and groaning sounds, which, though not frightful, were very peculiar,
and then the thump-thump, as of engines.

Very glad was he when the tunnel opened into another large cavern, at
the bottom of which was a lake. He could not have seen this had it not
been for the electric fluid which blazed like daylight from a great
globe overhead. On the margin of the lake were all kinds of hydraulic
machines, small as toys, but of every conceivable form; derricks and
wheels and screws and pumps, and all under the management of busy little
elves, who panted and puffed and tugged at ropes and wheels and pipes as
they worked, and kept up a constant chant not unlike the song of the
wind on a stormy night.

Leo watched them intently. Once in a while one restless little sprite
would turn a hose upon his companions, when the chant would stop long
enough for the rest to dip him head and heels into the lake, which had a
very quieting effect. Leo noticed great numbers of pipes running up the
sides of the cavern in all directions, but Knops soon opened the door of
what he called "the model-room," and here were new wonders displayed.

CHAPTER VI

The model-room of the elves' water-work department was a grotto of
salt--glittering, dazzling, sparkling, and flashing--divided into two
equal parts, or as if a huge shelf had been placed across it.

On the top of the shelf was a tiny park or forest, with all the natural
differences of the ground exactly represented by grasses, plants,
flowers, rocks, and trees, living and growing, but on a scale so small
that Leo was forced to use a microscope to properly enjoy its beauty.
Even the herbage was minute, and the trees no larger than small f