Mr. Blake lifted Hal across this, and showed him where there was a big crack in the water pipe. Then he showed Mab, also lifting her across the little pond in the cellar.
"You see the pipe was full of water," Mr. Blake explained, "and in the night it got so cold down cellar that the water froze, just as it did in the glass bottle out on the back porch.
"Then the ice swelled up, and it was so strong that it burst the strong iron pipe, splitting it right down the side."
"But why didn't the water spurt out when I came down cellar earlier this morning?" asked Mamma Blake. "It did not leak then."
"I suppose it was still frozen," answered her husband. "But when the furnace fire became hotter it melted the ice in the pipe and that let the water spurt out. But the plumber will soon fix it."
Hal and Mab watched the plumber, to whom their papa telephoned. He had to take out the broken pipe, and put in a new piece. Afterward Hal looked at the pipe that had been split by the ice.
"Why it's just as if gun-powder blew it up," he said, for once he had seen a toy cannon that had burst on Fourth of July, from having too much powder in it.
"Yes, freezing ice is just as strong as gunpowder, only it works more slowly," said Daddy Blake with a smile. "Powder goes off with a puff, a flash and a roar, but ice freezes slowly."
"Oh, but when are we going skating?" asked Mab, as she and her brother started for school, a little later that morning.
"As soon as I can find a frozen pond," said Daddy Blake with a smile.