"It is a very hard kind to describe, at any rate," said his father. "It is a kind of quivering, which begins in one place and spreads in every direction. Don't you hear a kind of a thumping sound?"
"Yes," said Rollo, "a great way off; what is it?"
"Look over across the pond there," said his father; "don't you see that man cutting wood?"
"Yes," said Rollo; "that's what makes the noise.—No, father," he continued, after a moment's pause, "that's not it. Look, father, and you'll see that the thumping sound comes when his axe is lifted up."
They all looked, and found that it was as Rollo had said. The strokes of the axe kept time, pretty well, with the sound of blows, which they heard, only the sounds did not correspond with the descent of the axe. When the axe appeared to strike the wood, they did not hear any sound, but they did hear one every time the axe was lifted up.
"So, you see," said Rollo, "it is not that man that we hear. There must be some other man cutting wood."
"We will wait a minute," said his father, "until he gets the log cut off, and then he will stop cutting; and we will see whether we cease to hear the sound."
So they sat still, and watched the man for a minute. Presently he stopped cutting,—and, to Rollo's great surprise, the sound stopped too.
"That's strange," said Rollo.
In a moment more, the man had rolled the log over, and commenced cutting upon the other side; and in an instant after he began to cut, Rollo began to hear the sound of strokes again.