dwiches and cake.

"Why do they call it 'Sugar-Loaf'?" asked the girl, looking far up to
the top of the mountain.

"I don't know," replied Chubbins.

"It's a queer name," said Twinkle, thoughtfully.

"That's so," agreed the boy. "They might as well have called it
'gingerbread' or 'rock-salt,' or 'tea-biscuit.' They call mountains
funny names, don't they?"

"Seems as if they do," said Twinkle.

They had been sitting upon the edge of one big flat rock, with their
feet resting against another that was almost as large. These rocks
appeared to have been there for ages,--as if some big giants in olden
days had tossed them carelessly down and then gone away and left them.
Yet as the children pushed their feet against this one, the heavy mass
suddenly began to tremble and then slide downward.

"Look out!" cried the girl, frightened to see the slab of rock move.
"We'll fall and get hurt!"

But they clung to the rock upon which they sat and met with no harm
whatever. Nor did the big slab of stone below them move very far from
its original position.

It merely slid downward a few feet, and when they looked at the place
where it had been they discovered what seemed to be a small iron door,
built into the solid stone underneath, and now shown to their view by
the moving of the upper rock.

"Why, it's a door!" exclaimed Twinkle.

Chubbins got down upon his knees and examined the door carefully. There
was a ring in it that seemed to be a handle, and he caught hold of it
and pulled as hard as he could. But it wouldn't move.

"It's locked, Twink," he said.

"What do you'spose is under it?" she asked.

"Maybe it's a treasure!" answered Chubbins, his eyes big with interest.

"Well, Chub, we can't get it, anyway," said the practical Twinkle; "so
let's climb the mountain."

She got down from her seat and approached the door, and as she did so
she struck a small bit of rock with her foot and sent it tumbling down
the hill. Then she stopped short with a cry of wonder, for under the
stone she had kicked away was a little hole in the rock, and within this
they saw a small golden key.

"Perhaps," she said, eagerly, as she stooped to pick up the key, "this
will unlock the iron door."

"Let's try it!" cried the boy.

Chapter II
Through the Tunnel

THEY examined the door carefully, and at last found near the center of
it a small hole. Twinkle put the golden key into this and found that it
fitted exactly. But it took