split the great, strong stone.

"There is scarcely anything that can stand against the swelling of
freezing ice. If you filled a big, hollow cannon ball with water, and
let it freeze, the ice would burst the iron."

"It burst our milk bottle once, I know," said Aunt Lolly.

"Yes," spoke Daddy Blake. "That is why, on cold mornings, the milkman
raises the tin top on the bottle. That gives the frozen milk a chance
to swell up out of the top, and saves the bottle from cracking."

"One morning last winter," said Mamma Blake, "when we had milk bottles
with the pasteboard tops, the milk froze and there was a round bit of
frozen milk sticking up out of the bottle, with the round pasteboard
cover on top, like a hat."

"And that's what saved the bottle from breaking," said Daddy Blake,
"If I had not wired down the cork of our bottle the water would have
pushed itself up, after it was frozen, and would have stuck out of the
bottle neck, like a round icicle."

"But what about our secret?" asked Hal. "Is it cold enough for you to
tell us about it?"

"I think so," answered Daddy Blake, with a queer little twinkle in his
eyes. "As long as the water in the bottle was frozen, the pond will
soon be covered with ice," he said. "And we need ice to make use of
the secret."

"Oh, I just wonder what it is?" cried Mab, clapping her hands.

"I think I can guess," spoke Hal.

Daddy Blake went out in the hall, and came back with two paper
bundles. He placed one at Mab's place, and gave the other to Hal.

"I want something, so I can cut the string!" Hal cried, and he laid
his package down on the floor, while he searched through his pockets
for his knife.

Just then Roly-Poly came into the breakfast room, barking. He saw
Hal's package on the floor, and, thinking, I suppose, that it must be
meant for him to play with, the little poodle dog at once began to
drag it away. Though, as the ground was frozen, I don't know how he
was going to bury it, if that was what he intended to do.

"Hi there, Roly!" cried Hal. "Come back with that, if you please,
sir!"

"Bow-wow!" barked the little poodle dog, and I suppose he was saying:

"Oh, can't I have it a little while?"

By this time Mab had her package open.

"Oh!" she cried. "It's skates! Ice skates! Oh, I've always wanted a
pair!"

"Ha! That's what I thought they were, when Daddy talked so much about
ice and freezing," said Hal.

He had managed, in the meanwhile, to get his bundle