CHAPTER XI.
THE SMOKE WHICH FALLS.
In the evening, after dinner, Monsieur Roger, to whom Paul recalled hispromise, asked Miette to go and find him a pebble in the pathway beforethe chateau. When he had the bit of stone in his hand, Monsieur Rogerlet it fall from the height of about three feet.
"As you have just heard and seen," said he, addressing Paul, "this stonein falling from a small height produces only a feeble shock, but if itfalls from the height of the house upon the flagstones of the pavement,the shock would be violent enough to break it."
Monsieur Roger interrupted himself, and put this question to Paul:
"Possibly you may have asked yourself why this stone should fall. Why dobodies fall?"
"Goodness knows," said the small voice of Miss Miette in the midst ofthe silence that followed.
"Miette," said Madame Dalize, "be serious, and don't answer for others."
"But, mamma, I am sure that Paul would have answered the same as Idid:--would you not, Paul?"
Paul bent his head slightly as a sign that Miette was not mistaken.
"Well," continued Monsieur Roger, "another one before you did askhimself this question. It was a young man of twenty-three years, namedNewton. He found himself one fine evening in a garden, sitting under anapple-tree, when an apple fell at his feet. This common fact, whosecause had never awakened the attention of anybody, filled all histhoughts; and, as the moon was shining in the heavens, Newton askedhimself why the moon did not fall like the apple."
"That is true," said Miette; "why does not the moon fall?"
"Listen, and you will hear," said Monsieur Dalize.
Monsieur Roger continued:
"By much reflection, by hard work and calculation, Newton made anadmirable discovery,--that of universal attraction. Yes, he discoveredthat all bodies, different though they may be, attract each other: theydraw towards each other; the bodies which occupy the celestialspaces,--planets and suns,--as well as the bodies which are found uponour earth. The force which attracts bodies towards the earth, which madethis stone fall, as Newton's apple fell, has received the name ofweight. Weight, therefore, is the attraction of the earth for articleswhich are on its surface. Why does this table, around which we findourselves, remain in the same place? Why does it not slide or fly away?Simply because it is retained by the attraction of the earth. I havetold you that all bodies attract each other. It is therefore quite truethat in the same way as the earth attracts the table, so does the tableattract the earth."
"Like a loadstone," said Albert Dalize.
"Well, you may compare the earth in this instance to a loadstone. Theloadstone draws the iron, and iron draws the loadstone, exactly as theearth and the table draw each other; but you can understand that theearth attracts the table with far more force than the table attracts theearth."
"Yes," said Miette; "because the earth is bigger than the table."
"Exactly so. It has been discovered that bodies attract each other inproportion to their size,--that is to say, the quantity of matterthat they contain. On the other hand, the farther bodies are from eachother the less they attract each other. I should translate in thisfashion the scientific formula which tells us that bodies attract eachother in an inverse ratio to the square of the distance. I would remindyou that the square of a number is the product obtained by multiplyingthat number by itself. So all bodies are subject to that force which wecall weight; all substances, all matter abandoned to itself, falls tothe earth."
Just here Miss Miette shifted uneasily on her chair, wishing to make anobservation, but not daring.
"Come, Miss Miette," said Monsieur Roger, who saw this manoeuvre, "youhave something to tell us. Your little tongue is itching to saysomething. Well, speak; we should all like to hear you."
"Monsieur Roger," said Miette, "is not smoke a substance?"
"Certainly; the word substance signifies something that exists. Smokeexists. Therefore it is a substance."
"Then," replied Miette, with an air of contentment with herself, "assmoke is a substance, there is one substance which does not fall to theearth. Indeed, it does just the opposite."
"Ah! Miss Miette wants to catch me," said Monsieur Roger.
Miette made a gesture of modest denial, but at heart she was very proudof the effect which she had produced, for every one looked at her withinterest.
"To the smoke of which you speak," continued Monsieur Roger, "you mightadd balloons, and even clouds."
"Certainly, that is true," answered Miette, naeively.
"Very well; although smoke and balloons rise in the air instead offalling, although clouds remain suspended above our heads, smoke andballoons and clouds are none the less bodies with weight. What preventstheir fall is the fact that they find themselves in the midst of theair, which is heavier than they are. Take away the air and they wouldfall."
"Take away the air?" cried Miette, with an air of doubt, thinking thatshe was facing an impossibility.
"Yes, take away the air," continued Monsieur Roger; "for that can bedone. There even exists for this purpose a machine, which is called anair-pump. You place under a glass globe a lighted candle. Then you makea vacuum,--that is to say, by the aid of the air-pump you exhaust theair in the globe; soon the candle is extinguished for want of air, butthe wick of the candle continues for some instants to produce smoke.Now, you think, I suppose, that that smoke rises in the globe?"
"Certainly," said Miette.
"No, no, not at all; it falls."
"Ah! I should like to see that!" cried Miette.
"And, in order to give you the pleasure of seeing this, I suppose youwould like an air-pump?"
"Well, papa will buy me one.--Say, papa, won't you do it, so we may seethe smoke fall?"
"No, indeed!" said Monsieur Dalize; "how can we introduce hereinstruments of physical science during vacation? What would Paul say?"
"Paul would say nothing. I am sure that he is just as anxious as I am tosee smoke fall.--Are you not, Paul?"
And Paul Solange, already half-conquered, made a sign from the corner ofhis eye to his little friend that her demand was not at all entirelydisagreeable to him.