"Perhaps," said his father. "We will try it and see. I will fill a
bottle with water, and we will set it out on the back porch to freeze.
If it freezes by morning I will know that I can tell you the secret."

"Oh, do we have to wait until morning?" cried Mab, in disappointed
tones.

"That won't be long," laughed her father. "You can hardly keep your
eyes open now. I guess the sand man has been here. Go to bed, and it
will soon be morning. Then, if there is ice in the bottle, I'll tell
you the secret."

Daddy Blake took a bottle, and filled it with water. He put the cork
in tightly, and then twisted some wires over the top.

"What are the wires for?" asked Hal.

"So the ice, that I think will freeze inside the bottle, will not push
out the cork," explained Daddy Blake. "Now off to bed with you!"

You may be sure Hal and Mab did not want to go to bed, even if they
were sleepy. They wanted to stay up and watch the water in the bottle
freeze. But Mamma Blake soon had them tucked snugly under the covers.

Then Daddy Blake fixed the furnace fire for the night, as it was
getting colder and colder. Next he opened a package he had brought
home with him. Something inside jingled and clanked, and shone in the
lamplight as brightly as silver.