‘My dear little girl, you are just asleep.’
‘Asleep! — O no, mother, I am not asleep at all,’ cried Lucy, rousing herself.
‘My dear, there is nothing shameful in being sleepy, especially at the hour, when it is time for you to go to bed. Only do not let me read to you, when you are sleepy, because you cannot possibly attend to what is read; and you would get the habit of hearing my voice going on, without minding or understanding what I say.’
‘O, mother! I beg your pardon: I assure you I heard the last words you read — it was something about punished as they thought proper; but I believe, mother, I was sleeping a little, too, for those words joined somehow with my dream, and I was dreaming about a saw, and sawing wood; and I thought, that, as I was sawing, I slipped, and saw, and wood, and horse and all, slipped, and were sliding down a hill; and just then I heard the words punished as they thought proper.’
‘I know the reason she is so shockingly sleepy,’ cried Harry; ‘it is because she worked so hard this morning, sawing; and she is not so strong, you know, as I am.’
‘There is nothing shocking,’ said his father, laughing—’ there is nothing shocking in your sister’s being sleepy. Good night, Lucy, my dear, go to bed. — Good night, Harry.’
‘No, father, not good night to me pray — I am not at all sleepy. I was thinking how I should like to live on that mountain, and slide down, with my pole in my hand, and learn to walk in dangerous places. But here there are no precipices, father; and I cannot learn to walk, as they do on Mount Pilate.’
‘This is a lamentable case indeed, Harry,’ said his father; ‘but, if you are so exceedingly anxious to learn to walk among precipices, I can tell you how a celebrated traveller says, that you may learn to do it, even in this flat country.’
‘Can you, father? — O, pray do tell me.’
‘Shut your eyes, and imagine yourself among precipices, and walk on; and M. de Saussure says, you may accustom yourself so to the idea of danger, that you would be much less terrified afterwards, if you were among real precipices, than another person would, who had never pursued this method.’
‘Is this true, father?’
‘I do not know, for I have never tried it. But I should think, that you might practise walking over a narrow plank, that was raised a foot from the ground, and, if you learn to balance your body, and walk well upon that, if you were not afraid, you would be better able to walk steadily over any narrow bridge, where there was a precipice, or water beneath.’
‘So I could,’ said Harry; ‘and I will try this experiment to-morrow. There is a long ladder, lying on the grass before the door, and I will walk on one side of the ladder, and Lucy on the other (for I suppose she will not be asleep to-morrow,) and we shall see who slips first. Good night, mother — good night, father — and thank you.’
Lucy was quite rested and refreshed, when she wakened the next morning; and she went into her father’s room, with her brother, at the usual hour.
The paper; which had been pasted over the hole in the bellows, was now dry; and Harry found, that, when he lifted up the top, the air came into the bellows at the nose; but it did not come in so readily, as when the hole in the bottom was open. Harry’s father now put a peg into the nose of the bellows, and desired Harry to blow. Harry, with great difficulty, lifted up the top of the bellows slowly. He knew, that this difficulty was occasioned by the shutting up the opening at the valve of the bellows and at the nose; and he asked his father, how any air could now get in.
His father told him, that bellows cannot be so well made, as to hinder the air from forcing its way into them, at the place where the nose is fastened to the leather; and that, besides this, the air gets in between the leather and the wood.
‘I see, father, the paper, which you pasted over the hole in the bellows, sinks inwards,’ said Harry, ‘when you lift the top, and swells outwards, when you shut it down.’
‘It does so, my dear; and, if the other parts of the bellows were air-tight (as it is called,) the paper would be broken inwards, when I pull up the bellows.’
‘I suppose, father, if it was not such strong paper, it would break now, when you lift it up suddenly.’
‘It would, my dear: — I will wet the paper, which will make it softer, and more fragile?
‘What is fragile, father.’
‘That which can be easily broken, Harry.’
‘Now you see, that lifting the top quickly has burst the paper.’
‘Yes, father, I see that the air, endeavoring to rush in, has broken the paper; the edges of it are all blown inwards.’
‘You perceive then, Harry, that the air, which is in the room and every where else, is always forcing itself into any empty space; and that, if it cannot force its way immediately, it drives any thing before it, which it can move, into that space.’
‘But I want to know,’ said Harry, ‘what makes the parts of air fly from each other,’ His father answered, that he did not know; ‘but I do know,’ said he, ‘that, if heat be added to air, the parts of the air separate from each other to a greater distance, and with greater force, than when they are colder. ‘Now, Harry,’ continued he, ‘I will close the valve, or door, of the bellows, and if we were to put the end of the bellows into this bowl of water, and, if we were to open the bellows, what would happen?’ — ? The water would go into the bellows,’ said Harry.
‘Why should it go in,’ said his father; ‘the parts of water, you know, do not fly from each other, in all directions, like those of air. If the bellows were lower than the bowl, the water might fall down into them; but you see, that the bellows are higher than the water.’
‘I do not think,’ said Harry, ‘that the water would move itself into the bellows; it is the air, on the outside of the water, which would rush into the bellows, if the water were not in the way; the air drives the water before it into the empty part of the bellows.’
Harry’s father then took a tumbler in his hand, and filled it with water, and said—’ If this tumbler, that is full of water, be emptied of the water, the air, that is in the room, will enter into the tumbler, whether it be held in any part of the room, upwards, or downwards, or sideways.’ He emptied the tumbler. ‘Now,’ continued he, ‘the air fills the space in the tumbler, which the water did fill; and, whichever way I hold the mouth of the glass, whether upwards or downwards, to this side or to that, the air would go into it, and fill it.’
‘So it is full of air, at this very moment, is it?’ said Lucy. ‘But how can you be sure of that, father! — because we cannot see the air.’
‘No; but we can feel it,’ said Harry. ‘ Wet your finger, and put it into the tumbler, and move it about quickly, and you will feel the air. — I hope you are satisfied now,’ added he, laughing, as Lucy gravely put her finger into the tumbler, and said, seriously, ‘ Yes, I am satisfied now.’
‘That is right, Lucy,’ said her father; ‘take nothing for granted. Now observe what happens, when I put this tumbler, with its mouth downwards into the water, in this basin. Does the water withinside of the tumbler rise higher than the water on the outside of it, or does it not rise so high?’
‘It does not rise quite so high,’ said Lucy. ‘What do you think is in that space, which you see above the water in the tumbler,’ Lucy, at first, hastily answered, that there was nothing; but, recollecting herself, she said there was air; and she just said the word air at the same moment when Harry said it.
‘And now suppose, that I could take away that air, which is in the glass, immediately over the water — What do you think would happen when that air was taken away,’ Lucy said, that she did not think that anything would happen.
Harry said, that he thought, that the water would rise in the glass, and fill the place, which the air had filled.
‘Very right, Harry,’ said his father—’ it would.’
‘O! to be sure, so it would,’ said Lucy; ‘but I did not say that, because I was thinking you meant quite a different sort o
f thing, father — When you said what would happen? I thought you meant to ask, if any accident would happen — if the glass would be broken suddenly, or something of that sort — O! to be sure, I know the water would rise in the glass.’
‘And do you know, Lucy, why it would rise in the glass, or what would make it rise,’ Lucy could not tell; all she could say was, that the water would rise, because there was room for it to rise; but her brother said he believed, that the air in the room, the air that was all over the water in this basin, in which the tumbler is turned down, would press upon that water, and, by pressing it so, would force it up into the glass, if there was no air, or any thing else in the glass, to prevent the water from rising.
His father, without telling Harry whether he was right or wrong, said, that he would try this for him.
But just then their mother came in, and told their father, that breakfast had been ready some time; and she was afraid, that, if he did not come soon, the muffins would be quite cold. Immediately, their father made a great deal of haste to get ready — Harry smiled, and said—’Ha! ha! — see what haste father makes, now he knows the muffins are come! — he loves muffins, I see, as well as I do!’
‘I dare say he loves muffins, and so do I,’ said Lucy; ‘but I know, Harry, it is not all for the sake of the muffins, that he is making this wonderful haste — there’s another reason.’
‘What other reason,’ said Harry.
‘Because,’ whispered Lucy, ‘he loves mother, as well as muffins, ‘and he does not like to keep her waiting for breakfast always; particularly when she is so good, you know, and is never angry.’
‘I wonder whether you will be as good, when you grow up,’ said Harry, laughing—’No, no; I dare say, you will frown, this way, at your husband, and say, ‘I wonder, Mr. Slow, you are never ready for breakfast!’
‘Now, father! this morning,’ said Harry, ‘I hope we are to see the experiment, which you were going to show us yesterday, just when mother and the muffins came. You know, father, that you asked us what would happen, if you could take away all the air, that is in this tumbler, between the top of the water and the glass, and Lucy said nothing would happen; but she was wrong.’
‘Only at first, brother; I was only wrong at first, when I did not understand father’s question; afterwards, you know, I was as right as you were, for I said the water would rise up higher in the glass, to be sure.’
‘Yes, but then you did not know the reason why it would rise, and I did; for when father asked me, I said, that the air in the room, the air, that is all over the water in this basin, in which the tumbler is turned down, would press upon that water, and force it up into the glass, if there was no air left in the glass, to hinder it.’
‘Well, I know that,’ said Lucy, ‘as well as you.’
‘Yes, when I tell it you,’ cried Harry; ‘but I said it at first; I was right from the beginning.’
‘Come, come, my dear children, no boasting, Harry — no disputing, Lucy; and then you will both be right. What signifies, which of you said it first, if you both know it at last? Now, Harry, turn your attention to this, and you, Lucy: I am going to try an experiment, that will prove to you whether the water will or will not rise in the glass, when some of the air above it is taken away.’
‘But I can’t imagine, father,’ said Harry, ‘ho w you will contrive to get all that air out of the glass.’
‘I cannot easily get all the air out of the glass — I cannot easily produce what is called a perfect vacuum, that is, a place where there is nothing, no air, nor any thing else; but, though I cannot produce a vacuum in the top of this glass, by taking away all the air, I can easily take away some of it.’
‘How, father?’ said Harry and Lucy at once — Their father answered,—’You shall see?’
Then he went for a crooked, or bent tube of glass — it was nearly in the shape of a capital U — He told Harry, that tubes of this sort are called syphons. He put one leg of this tube under the bottom of the tumbler, up through the water in the tumbler, into the place which appeared empty.
He now bid Harry suck at the other end of the syphon — Harry did so; and as fast as he sucked, the water rose in the tumbler; but, when Harry took away his mouth, the water fell again.
‘Why does this happen, Harry.’
‘It happens, I believe, father, because, when I sucked, I took away the air, that was above the water in the tumbler; and when I left off sucking, and took my mouth away, the air went again through the syphon into the tumbler above the water.’
‘Just so, Harry. Now the same thing would happen if I could take away the air, or lessen it, by any means, in the tumbler. If I could fill, or partly fill, the tumbler, with any thing that could be taken away from beneath the tumbler, while it stands in the water that is in the basin, then we should see the water rise in the tumbler, in the same manner as if the air were sucked out of it — What shall we put into it that we can readily take out, without disturbing the tumbler?’
‘I don’t know,’ said Harry.
‘Here,’ said his father, ‘is a little spool, or roller, upon which silk is usually wound — Now I will put this into a little frame of tin, that will support it under the glass tumbler above the water. Upon this, I have wound some very broad tape so as to fill up a large space in the tumbler: I pull one end of the tape under the bottom of the tumbler, through the water that is in the saucer, so that I can unwind the whole of the tape without disturbing the tumbler. You see, that the water rises in the tumbler, as I unwind, and draw out the tape; and, now that all is drawn out, the water has filled as much of the tumbler as had before been filled by the tape.’
‘That is very pretty,’ said Harry; ‘I understand it. When the tape was taken away, the room, that it filled would have been supplied with air, if air could have got into the tumbler; but, as it could not get in, it forced the water in the basin to go up into the tumbler.’
‘Now I will show you, my dear children, another method of trying this experiment. I make a little stand of halfpence under the tumbler, upon which I can put a piece of paper, without its being wet by the water in the basin — I set fire to the paper; and whilst it is flaming, I put the tumbler quickly over the flame into the water — now you see the flame goes out and the water rises.’
‘Yes, father; I suppose the flame burns out some of the air.’
‘It does, Harry, consume a little of the air in the tumbler; but that is not the cause why so much water rises. You saw, that the flame took up a considerable quantity of room in the tumbler while it was burning; but, the moment that the glass covered the flame it went out: and then the room, which the flame took up, was supplied by the water, rising from the saucer.’
‘Yes, father, the water was driven in by the air, that wanted to get into the tumbler.’, — Just so, Harry. Now, instead of putting a piece of lighted paper upon the little stand of halfpence, I put a piece of tow, dipped in turpentine upon it; this, you see, makes a larger flame; and, when this is extinguished, or put out, by placing the glass quickly over it, more water rises than in the former experiment: and, if I were to dip the tow into spirit of wine, and light it, it would answer the same purpose as tow dipped in turpentine.’
Their father warned the children against the danger of having more than a very small quantity of turpentine or spirit of wine brought near to the candle or to the fire, as it might easily catch fire, and set fire to their clothes, or to the furniture in the room. ‘All experiments in which fire is necessary,’ their father said, ‘children should never attempt to try, when they are in a room by themselves. — Some grown-up person should always be present, to prevent accidents, or to assist, if any accident should happen.’
The children both promised their father, that they would take care never to meddle with fire when he or their mother was not present, or to try any dangerous experiments.
Harry then turned again to look at the tumbler, and repeated, that it was really very pretty, to see the water rise
in the tumbler, pressed up by the air, that was over the water in the basin. Harry seemed still doubtful whether Lucy understood it.
‘You see, Lucy, the air presses this water first, and that presses it up into the tumbler.’ Yes, I understand it perfectly,’ said Lucy.
‘But, Harry,’ said his father, ‘you say that the air presses the water in the basin, up in the glass tumbler. What do you think would happen, if there was no water in the basin.’
‘I believe the water would run out of the tumbler,’ said Lucy.
‘So it would,’ said her father, ‘unless the bottom of the glass was ground quite smooth, and the basin also ground quite smooth.’
‘And what would happen, if the basin and tumbler were ground quite smooth?’ said Harry.
‘Then,’ replied his father, ‘if you lifted up the tumbler, the basin would come up with it from the table, and seem to stick to it.’
‘I should like very much to see that experiment,’ said Lucy; ‘but we have no glass vessel nor basin ground smooth enough, I believe.’
‘No; but I can show you an experiment equally satisfactory, without them,’ said their father.
‘I fill this ale glass with water, and I cover it with a card, having first wetted the side of the card, which is next to the glass — I now put the palm of my hand on the card, and I turn the glass upside down on the card, which lies on my hand. You now see, that, though I have taken away my hand, the card sticks to the glass.’
‘That is very pretty!’ cried Lucy.
‘But why does not the water fall out?’ said Harry.
‘Because the card keeps it in,’ said Lucy.
‘Why does it keeps it in,’ said Harry.
‘Because the card sticks to the glass,’ said Lucy.
‘And what makes it stick to the glass,’ said Harry.
Lucy did not answer immediately; but her father asked Harry if he knew.
Harry said it did not stick to the glass; but it is held close against the glass by the pressure of the air that is in the room.’
Complete Novels of Maria Edgeworth Page 354
