"Yes," added Monsieur Dalize; "but it was interesting to know why the apple fell, and you have taught us."
"That is true," cried Miette; "only you have forgotten to tell us why the moon does not fall."
"I have not forgotten," said Monsieur Roger; "but I wished to avoid speaking of the attraction of the universe. However, as Miette obliges me, I shall speak. You see that all earthly bodies are subject to a force which has been called gravity, or weight. Now, gravity can also be called attraction. By the word attraction is meant, in fact, the force which makes all bodies come mutually together and adhere together, unless they are separated by some other force. This gravity or attraction which the terrestrial mass exerts upon the objects placed on its surface is felt above the soil to a height that cannot be measured. Learned men have, therefore, been led to suppose that this gravity or attraction extended beyond the limits which we can reach; that it acted upon the stars themselves, only decreasing as they are farther off. This supposition allows it to be believed that all the stars are of similar phenomena, that there is a gravity or attraction on their surface, and that this gravity or attraction acts upon all other celestial bodies. With this frame of thought in his mind, Newton at last came to believe that all bodies attract each other by the force of gravity, that their movements are determined by the force which they exert mutually upon one another, and that the system of the universe is regulated by a single force,—gravity, or attraction."
"But that does not explain to us why the moon does not fall," said Monsieur Dalize.
Monsieur Roger looked at his friend.
"So you also," said he, smiling,—"you also are trying to puzzle me?"
"Of course I am; but I am only repeating the question whose answer Miette is still awaiting."
"Yes," said Miette, "I am waiting. Why does not the moon fall?"
"Well, the moon does not fall because it is launched into space with so great a force that it traverses nearly four-fifths of a mile a second."
Miette ran to open the door of the vestibule. The park was bathed in the mild light of a splendid moon.