This attraction is
what gives every thing weight.
"If I lift up any thing, I am acting against this force, for which
reason the article seems heavy; and the more matter it contains, the
greater is the force of attraction and the heavier it appears to me."
"Then," said Lucy, "if this attraction is so powerful, why do we not
stick to the ground?"
"Because," replied her father, "we are animate beings, and have the
power of motion, by which, to a limited degree, we overcome the
attraction of the earth."
"Well then, father," said Lucy, "if our power of motion can overcome the
attraction, why can not we jump a mile high as well as a foot?"
"Because," replied her father, "as I said before, we can only overcome
the attraction to a certain extent. As soon as the force our muscles
give to the jump is spent, the attraction of the earth pulls us back."
"Did Sir Isaac Newton think of all these things, because he saw the
apple fall?" inquired Lucy.
"Yes; of all these and many more. He was a man of great knowledge. The
name by which the force he discovered is generally known, is the
Attraction of Gravitation, and some time you will learn how this force
keeps the earth, and the sun, moon, and stars, all in their places.
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