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.

"Yes, my dear fellow, there's no doubt of that; the heat is tremendous.
Now some of your thermometers go no higher than one hundred and thirty,
while ours can ascend to three and four hundred; that is, for the common
air of our dwellings. Of course the heat demanded by many of our
experiments is practically incalculable; for instance--"

"Oh, get me out of this!" entreated Leo.

"Here, step into this niche, put your mouth to this opening"--and Knops
pointed to one of many silver tubes which projected near them--"now
breathe. Is not that refreshing?"

"Yes," said Leo, reviving, as he took a long draught of fresh cool air.
"How do your people endure such heat?"

"They are used to it; besides, they can come to these little tubes, as
you have done, whenever they please."

"Where does this air come from?"

"It is pure oxygen; we manufacture it, and here is a lump of pure
carbon which we also manufacture," and he laid in Leo's hand what looked
like a drop of dew. It was a diamond of exquisite lustre.

As Leo looked with surprise and admiration at it, an elf came staggering
up to the niche. After breathing the oxygen he turned to Knops with a
heart-rending cry.

"I have lost it--lost it, Master Knops."

"Lost