er. A little child
would be able to move them; but still they would move exceedingly slow
at first, and it would be hard to stop them, when they were in motion.
So, he said, if the earth should cease to attract and draw down any
great, heavy body, like a large stone, for example, the smallest child
could lift it, though it would come up slowly, just as a very heavy body
would move, if it was suspended by a string, or was afloat upon the
water.

"And so," said Rollo, "if the earth should not attract us, could we push
ourselves right up off from the ground?"

"Yes," said his father, "most undoubtedly."

"What, and go about anywhere in the air?"

"Certainly."

Rollo began to laugh aloud at this idea, and looked very much interested
and pleased.

"O, then I wish there was no gravitation," said Rollo; "I do, really."

"But, then," continued his father, "if you should get up into the air,
you could not get down again."

"Why not?" said Nathan, beginning to look a little concerned.

"Unless," said his father, "you had something above you, to push
against, so as to push yourselves down. You would be just like a boy in
a boat, off from the shore, and without any paddle or pole. He could not
get back again."

"We might tie a rope to something," said James, "before we went up, and
so pull ourselves down."

"Yes, that you might do."

"And could not we flap our hands, like a bird, and so fly a little?"

"Perhaps you could," said his father.

Here the children all began to flap their hands, like young birds trying
to fly; and Rollo said again, he wished, with all his heart, there was
no gravitation; "for then," said he, "we should have strength enough to
fly."

"That would lead to serious consequences," said his father.

"What consequences?" said James.

"Much more serious than you would suppose."

"Tell us what they would be, uncle," said James.

"O, I know," said Rollo; "you could not stand up straight without
gravitation."

"O, we could, couldn't we, father?" said Nathan.

"What makes you think, Rollo," said his father, without replying to
James's question--"what makes you think that we could not stand up
straight without gravitation?"

"Why, you see," said Rollo.--Here he paused, and looked confused, and
did not know what to say. He had an indistinct recollection of having
read something about it in some book; but he could not tell what.

"I don't see what should prevent any body's standing up strai