ght, if the
attraction of the earth should cease; in fact, if it made any
difference, it would be rather easier to stand up straight."

Here Rollo looked rather foolish, but he did not reply. The truth is,
like almost all other children, who take an interest in reading, he was
sometimes a little vain of his knowledge; and in this case, instead of
listening attentively, and endeavoring to learn something new from his
father's explanations, he seems to have thought it a good plan for him
to help him elucidate the subject to James and Nathan. He exchanged the
character of learner for teacher too soon.

"Well, uncle," said James, "what would be the consequence if gravitation
should cease?"

"Why, in the first place," said Rollo's father, "all the streams in the
world would stop running."

"The streams!" said Rollo, astonished.

"Yes," said his father, "every river, brook, and rill. The reason why
the streams flow is, that the earth attracts the water from the
mountains and hills, down into the valleys and towards the sea."

"Well, sir, what else?" said Rollo.

"Why, there would never be any more rain."

"No more rain!" exclaimed all the children.

"No," he replied. "The drops of rain fall only because the earth draws
them down by its attraction; and, of course, if this attraction should
cease, they would remain where they are."

The children were musing a minute upon these strange effects, when Rollo
asked if anything else would happen.

"Why, yes," said his father, "worse disasters than these; but I do not
know whether you would understand them, if I should explain them."

"O, try," said Rollo; "I think we shall understand."

"Well, let me think," said his father. "You have noticed how a chaise
wheel, on a muddy road, in a wet day, holds the mud upon it, until when
it is going very swiftly down a hill, and then the mud flies off in all
directions."

"Yes, sir," said all the children.

"And if the mud did not stick to the wheel pretty tight, it would be
thrown off at all times, even when the wheel was going slow. You
understand this."

"Yes, sir."

"Well, now, this whole earth, you all know, is whirling around
through space, and moving on also around the sun. And all the loose
things upon the surface would be thrown off at once, if they were
not held to it by a strong attraction. If this attraction were to
cease suddenly,--whisk!--away we should all go in an instant--rocks,
houses, men, animals, all i