"Oh, does ice ever get as thick as that?" asked Hal.

"Oh, yes, and much thicker. On big lakes it gets over two feet thick in cold weather," Mr. Blake said. "Then it will hold up a whole regiment of soldiers, and cannon too. Ice is very strong when once it is well frozen. But always be sure it is thick enough before going on."

"How are you going to tell?" asked Mab.

"By cutting a little hole through the ice," her father told her. "You can look at the edges of the hole and tell how thick the ice is. We will try it and see."

With the big blade of his knife, Mr. Blake cut and chipped a hole in the ice, a little way from sh.o.r.e. Hal and Mab stayed on the ground watching their father, but Roly-Poly ran all about, barking as hard as he could.

"I guess he is looking for something to bury in a hole," spoke Hal.

But Roly could not dig in the hard ice, and the ground was also frozen too solidly for him to scratch. So all the little poodle dog could do was to bark.

"There we are!" cried Mr. Blake, after a bit. "See, children, the ice is more than six inches thick. It will be safe for us to skate on!"

Hal and Mab ran to look into the little hole their father had cut in the ice. It went down for more than half a foot, or six inches, like a well you dig in the sand at the seash.o.r.e. But no water showed in the bottom of this hole in the ice.

"The ice is good and thick," said Mr. Blake. "It will hold up all the skaters that will come on this pond."

But the children and their Daddy were the only ones there now. Mr.

Blake showed Hal and Mab how to put on their skates. He made the straps tight for them, and then put on his own.

"Now we will see how well you can skate," said Mr. Blake.

"I can!" cried Hal. "I've watched the big boys do it. I can skate!"

"It's just like roller skating," said Mab, "and I can do that, I know."

"Well, you may find it a little different from roller skating, Mab,"

her papa answered with a laugh.

"Here I go!" cried Hal. He struck out on the ice, first with one foot, and then with the other, as he had been used to doing on his roller skates. And then something happened.

Either Hal's feet slid out from under him, or else the whole frozen surface of the pond tilted up, and struck him on the head. He was not quite sure which it was, but it felt, he said afterward, as though the ice flew up and struck him.

"Oh, be careful!" cried Daddy Blake, as he saw Hal fall. But it was too late to warn the little boy then.

"Oh, he's hurt!" exclaimed Mab with a little sob, as she saw that her brother did not get up.

Daddy Blake skated over to Hal, but there was no need of his help. For Hal got up himself, only he was very careful about it. He did not try to skate any more. He did not want to slip and fall.

"Are you hurt?" asked Mr. Blake.

"N-n-no; I guess not," Hal answered slowly. "The ice is sort of soft, I guess."

"No quite as soft as snow, however," laughed Daddy Blake. "Now you had better not try to skate until I take hold of your hand. I will hold you up. Come, Mab, well take hold of hands and so help each other to stand up."

Roly-Poly was rushing here and there, filled with excitement, and he was barking all the while. He was having fun too.

"Now strike out slowly and carefully," directed Daddy Blake to the children. "First lean forward, with your weight on the left foot and skate, and then do the same with your right. Glide your feet out in a curve," and he showed them how to do it, keeping hold of their hands, Mab on one side and Hal on the other. In this way they did not fall down.

Slowly over the ice they went.

"Oh, we are skating!" cried Mab, in delight.

"Isn't it fun!" shouted Hal.

"At least you are beginning to skate," said Mr. Blake.

Roly-Poly kept prancing around in front, running here and there, and barking louder than ever.

"Don't get in our way, Roly!" called Mr. Blake with a laugh, "or we might skate right over you!"

"Bow-wow!" barked the little poodle dog. And I suppose that was his way of saying:

"No, I won't! I'll be good."

Hal and Mab were beginning to understand the first simple rules of skating. It was not as easy as they had thought--nor was it the same as roller skating. The ice was so slippery.

"Oh, look at Roly!" cried Hal, when they had stopped for a rest. "He's skating, too."

A boy who had no skates had come down to the frozen pond, and, seeing the poodle dog, and knowing him to be Hal's pet, this boy wanted to have some fun. He would throw a stick on the ice, sliding it along, and Roly would race after it. He would go so fast, Roly would, that he could not stop when he reached the stick, and along he would slide, almost as if he were skating.

Just as Hal called to Mab to look, Roly cook a long run and a slide.

Then, all of a sudden, there was a cracking sound in the ice. A hole seemed to open, close to where the poodle dog was, and, a moment later, Roly-Poly went down, out of sight, into the cold, black water.

"Poor Roly-Poly!" cried Mab. "He's drowned!"

Roly-Poly had gone under the ice. Hal and Mab were ready to cry. But listen. This is a secret. Roly-Poly was not drowned! A wonderful thing happened to him, but I can not tell you about it until the end of the book. And mind, you're not to turn over the pages to find out, either.

That would not be fair. Just wait, and I'll tell you when the times comes.

CHAPTER VI

FISHING THROUGH THE ICE

"Come on, Mab," cried Hal, to his sister. "We've got to get him out!

We've got to save Roly-Poly!"

Letting go his father's hand, Hal started to skate toward the place where the little poodle dog had last been seen.

"Wait--don't go," said Mr. Blake quickly, but there was no need. For, as soon as Hal let go of his Daddy's hands, his feet, on which were still the slippery skates, slid out from under him, and down he went again.

"Oh dear!" cried Mab. "Everything is happening! Can't we save Roly, Daddy?"

"Yes, perhaps," he said slowly. "But we must not go too near. Roly went down through an air hole in the ice. The ice is thin near there.