the boy.

"Why did you do that?" he asked in surprise.

Woot sat up and gazed around him in amazement.

"I--I don't know!" he replied.

The two tin men, arm in arm, started to pass them, when both halted and
tumbled, with a great clatter, into a heap beside Woot. Polychrome,
laughing at the absurd sight, came dancing up and she, also, came to a
sudden stop, but managed to save herself from falling.

Everyone of them was much astonished, and the Scarecrow said with a
puzzled look:

"I don't see anything."

"Nor I," said Woot; "but something hit me, just the same."

"Some invisible person struck me a heavy blow," declared the Tin
Woodman, struggling to separate himself from the Tin Soldier, whose legs
and arms were mixed with his own.

"I'm not sure it was a person," said Polychrome, looking more grave than
usual. "It seems to me that I merely ran into some hard substance which
barred my way. In order to make sure of this, let me try another place."

She ran back a way and then with much caution advanced in a different
place, but when she reached a position on a line with the others she
halted, her arms outstretched before her.

[Illustration]

"I can feel something hard--something smooth as glass," she said, "but
I'm sure it is not glass."

"Let me try," suggested Woot, getting up; but when he tried to go
forward, he discovered the same barrier that Polychrome had encountered.

"No," he said, "it isn't glass. But what is it?"

"Air," replied a small voice beside him. "Solid air; that's all."

They all looked downward and found a sky-blue rabbit had stuck his head
out of a burrow in the ground. The rabbit's eyes were a deeper blue than
his fur, and the pretty creature seemed friendly and unafraid.

"Air!" exclaimed Woot, staring in astonishment into the rabbit's blue
eyes; "whoever heard of air so solid that one cannot push it aside?"

"You can't push _this_ air aside," declared the rabbit, "for it was made
hard by powerful sorcery, and it forms a wall that is intended to keep
people from getting to that house yonder."

"Oh; it's a wall, is it?" said the Tin Woodman.

"Yes, it is really a wall," answered the rabbit, "and it is fully six
feet thick."

"How high is it?" inquired Captain Fyter, the Tin Soldier.

"Oh, ever so high; perhaps a mile," said the rabbit.

"Couldn't we go around it?" asked Woot.

"Of course, for the wall is a circle," explained the rabbit. "In the
center of the circle s