Mary.

"It's just dandy!" shouted Hal, clapping Charlie on the back. Then, as
he saw that Charlie was carrying his sister Mary's skates, Hal took
Mab's and put them on a strap with his own, saying:

"I'll carry them for you, Mab!"

"Thank you," she said, most politely. "You are very kind."

"Well, do you like my little surprise?" asked Daddy Blake as they
started off toward the lake, to hold their winter pic-nic.

"Surely we do!" answered Hal. "It's fine that you asked Mary and
Charlie to come with us."

It was quite cold out in the air, and, as Mab had said, it did look
like snow. There were dull, gray clouds in the sky, and the sun did
not shine. But the children were happy for all that. In a little while
they reached the big frozen lake, and, putting on their skates they
started to glide over the ice.

"We will skate about a mile, and then we will rest, and have a little
skating race, perhaps, and afterward we can eat our lunch."

"And what will we do after that?" asked Charlie.

"Oh, skate some more," answered Daddy Blake. "That is if you want to."

The children had much fun on their skates.

And once, when Charlie sat down on the ice, to punch with his knife a
hole in his strap, so that it would fit tighter, something happened.
Charlie laid down his knife, and when he went to pick it up, he found
that it had sunk down in the ice, making a little hole for itself to
hide in.

"Oh, look here!" he cried. "My knife has dug down in the ice just like
your dog Roly-Poly used to dig a hole for a bone."

"Poor Roly!" sighed Mab. "I wish we had him now!"

"But he's gone," said Hal. "Well never see him again," and he looked
at Charlie's knife down in the ice. "What made it do that, Daddy?" he
asked. "What made it sink down?"

"The knife was warmer than the ice, and melted a hole in it,"
explained Mr. Blake. "The knife was warm from being in Charlie's
pocket.

"I read once about some men who went up to the North Pole," he
continued. "They had with them a barrel of molasses, but it was so
cold at the North Pole that the molasses was frozen solid. When the
men wanted any to sweeten their coffee they would have to chop
out chunks with a hatchet. They had very little sugar and so used
molasses.

"Once one of the men, after chopping some frozen molasses for
breakfast, forgot what he was doing, and left the hatchet on top of
the solid, frosty sweet stuff in the barrel. The next time he wanted
the hatchet to cho