Doctor B — let Harry examine them. And he was so good, as to answer all the questions that either Lucy or Harry asked him. Harry asked him, what that shining liquid was, which he saw in the tube of the barometer.
Doctor B. It is a metal called quicksilver; and it is found in mines under ground.
Harry. My father showed me quicksilver the other day, and it was liquid, and was spilt on the table, and on the floor; and how can that be a metal? I thought metals were all solid.
Doctor B. So they all are, when they are sufficiently cold.
Harry. Then is quicksilver hotter than iron?
Doctor B. I cannot explain to you, at present, what you want to know.
Harry. What is that globe made of?
Doctor B. Of pasteboard and plaster.
Harry. How is it made round? I thought pasteboard was made of flat sheets of paper, pasted upon one another.
Doctor B. Flat pasteboard is; but the pasteboard upon this globe is made round, by means of a round mould, upon which it is formed — You know, I suppose, what a mould is?
Harry. Yes, I do, pretty well. But how can the pasteboard, after it is all pasted together, be gotten off a round mould?
Doctor B. After it is dry, it is cut all round with a knife; and then it will come off the mould in two caps, as the shell of a nut, when it is opened with a knife, comes off the kernel.
Harry. What is the use of this machine, which you call an air-pump?
Doctor B. To pump air out of that glass vessel, which you see.
Harry. I do not quite understand you, sir.
Doctor B. No, my dear, it is not probable, that you can; but I will soon give you a little book, which will teach you the uses of several instruments of this sort.
Harry. My dear uncle, I cannot tell you, how much I shall be obliged to you.
Harry and Lucy were much delighted with what they saw at their uncle’s; and as they had not been troublesome, he asked their father and mother, to bring them to Flower-hill, when they next came to see him.
They returned home that evening, just before it was dark, and went to bed by moonlight.
Thus ends an account of three days passed by Harry and Lucy. One day when Harry was about five, and Lucy six years old. And two days, a year afterwards, when Lucy was seven, and Harry six years of age.
PART III. NOTE TO PARENTS.
We are afraid, that the following pages should appear too difficult for children of eight or ten years old, if their thoughts have not been turned to subjects of the sort, which are here introduced to their attention. We, therefore, most earnestly deprecate the use of the following book, till the understandings of the pupils, into whose hands it may be put, shall have been previously accustomed to the terms, and to the objects, which are mentioned in the following parts of Harry and Lucy.
The intention of the writers is to prepare the mind for more difficult studies; and the end, which they have in view, will be completely frustrated, if this little book is crammed into the minds of children. It is intended to be used in very short portions, and not to be formed into necessary tasks; but to he read when the child’s mind has been prepared, by what it has already seen and heard, to wish to hear and see more. —
That these lessons (not tasks) are in themselves intelligible to children, we are certain; because they have been readily comprehended by several young children, and in particular by a boy of four years and two months old. All the experiments herein related were shown to him, at different times, within a fortnight. He was much entertained. His lessons were short, but his attention was engaged, and he seemed to wish for their return with eagerness. That he did, and does understand them thoroughly, and that he has not been taught certain answers to certain questions by rote, we assert. In making this assertion, we do not mean to claim any superiority for this child over other children; because we believe him to be no prodigy, but a child of good abilities, without any peculiar cleverness. So far from making any such claim, we must acknowledge, that this boy scarcely knows his letters; and, that he shows no extraordinary quickness in learning them. He is, however, lively and obedient; indeed, the most lively children are, if well treated, usually the most obedient. The names of various objects, of common and of uncommon use, are familiar to him; he has seen a variety of tools, and has been accustomed to handle a few of them. In short, in his education, nothing extraordinary has been said, or taught, or done. Every governess, and every mother, who acts as governess to her own children, may easily follow the same course. Where mothers have not time, and where they cannot obtain the assistance of a governess, it were to he wished, that early schools could be found for early education. To learn to read is to acquire a key to knowledge; but alas! it is a key, that is not always used to advantage. There is not an hour in the day, when something useful may not be taught, before books can be read, or understood. Perhaps parents may pity the father and mother, in Harry and Lucy, as much as they pity the children; and may consider them as the most hard-worked, and hard-working people, that ever existed, or that were ever fabled to exist. They may say, that these children never had a moment’s respite, and that the poor father and mother had never any thing to do, nor ever did any thing, but attend to these children, answer their questions, and provide for their instruction or amusement. This view of what is expected from parents may alarm many, even of those, who have much zeal and ability in education But we beseech them not to take this false alarm. Even if they were actually to do all, that the father and mother of Harry and Lucy are here represented to have done, they would not, in practice, feel it so very laborious, or find that it takes up so preposterous a portion of their lives, as they might apprehend. In fact, however, there is no necessity for parents doing all this in any given time, though there was a necessity for the authors bringing into a small compass, in a reasonable number of pages, a certain portion of knowledge.
Be it therefore hereby declared, and be it now and henceforward understood, by all those, whom it may concern, that fathers or mothers (as the case may be) are not expected to devote the whole of their days, or even two hours out of the four and twenty, to the tuition or instruction of their children. That no father is expected, like Harry’s father, to devote an hour before breakfast to the trying of experiments for his children. That no mother is required to suspend her toilette — no father to delay shaving — while their children blow bubbles, or inquire into the construction of bellows, windmill, barometer, or pump. And be it farther understood, that no mother is required, like Lucy’s mother, to read or find every evening entertaining books, or passages from books, for her children.
Provided always, that said fathers and mothers do, at any and all convenient times, introduce or suggest, or cause to be introduced or suggested to their pupils, the simple elementary notions of science, contained in the following pages; and provided always that they do at all times associate, or cause to be associated, pleasure in the minds of their children with the acquisition of knowledge.
Richard Lovell Edgeworth, and Maria Edgeworth.
PART III.
It was Lucy’s business to waken her father every morning. She watched the clock, and, when it was the right time, she used to go softly into her father’s room, and to open the curtain of his bed, and to call him.
‘Father! father! it is time for you to get up!’ Then she drew back the window curtains and opened the shutters — and she put every thing ready for him to dress. She liked to do this for her father, and he liked, that she should do it for him; because the attending upon him taught her to be neat and orderly. She and her brother Harry both liked to be in the room with their father, when he was dressing; because then he had leisure to talk to them. Every morning he used to tell or teach them something that they did not know before.
One morning, at the beginning of winter, when the weather was cold, Lucy said —
‘It is much colder in this room to-day, father, than it was when you got up yesterday.’
‘O no! I think it is
not nearly so cold today as it was yesterday, when my father was dressing,’ said Harry.
‘What do you think, father?’ Their father went and looked at something, that hung in his window, and then answered—’ I think, that it is neither hotter nor colder in this room to-day than it was yesterday, at the time when I was dressing.’
‘Are you sure, father?’ said Lucy.
‘Quite sure, my dear.’
‘How can you be quite sure, father?’ said Lucy—’ How do you know?’
‘I can tell how father knows,’ cried Harry—’ he looked at the thermometer.’
‘But how does he know by looking at the thermometer?’ said Lucy.
‘Come here, and I will show you, for I know,’ cried Harry—’ Stand up on this chair, beside me, and I will show you; my uncle told me about it last summer, when I was looking at the thermometer at his house.
‘Look, do you see this glass tube?’
‘Yes; I have seen that very often.’
‘I know that; but do you see this part of the tube, at the top, seems to be empty; and this part of it here, at the bottom, and half way up the glass tube, is full of something white — Do you know what that is?’
‘Yes; I remember very well my uncle told me, that is quicksilver; but what then? ‘Stay, be patient, or I cannot explain it to you. Do you see these little marks, these divisions marked upon the edge here, upon the ivory, by the side of the glass tube?’
‘Yes: well?’
‘And do you see these words printed?’
‘Yes: freezing, temperate, blood heat, boiling-water heat — I have read those words very often, but I don’t know what they mean.’
‘When it is neither very hot nor very cold, people say it is temperate; and then the quicksilver will be just opposite to that division where temperate is written. When it freezes, the quicksilver would be down here at the freezing point; and, if this thermometer were put into boiling water, the quicksilver would rise up, and it would be just at the place where boiling-water is written. Blood heat, I believe, means the heat that people’s blood is of generally — I am not sure about that. But look, here are the numbers of the degrees of heat or cold. Boiling-water heat is 212 degrees: and when it is freezing it is 32 degrees.’
‘And the heat of this room now is — Look, what is it, Lucy?’
Lucy said it was above the long line marked 40.
‘Count how many of the little divisions it is above 40,’ said Harry.
She counted, and said seven: and her father told her to add that number to 40, which made 47.
Then Lucy asked how her father had known that it was as cold, and no colder in his room to-day, than it was yesterday morning.
‘Because, yesterday morning, the quicksilver rose just to the same place, to 47 degrees, as it does to-day. It always rises or falls with the same degree of heat or cold, to the same place — to the same degree.’
‘But look, look, it is moving! The quicksilver is rising, higher and higher, in the glass!’ cried Lucy. ‘Look! now it is at fifty — fifty-two — fifty-five—’
‘Yes: do you know the reason of that,’ said Harry.
‘No; I do not know,’ said Lucy: ‘for it is not in the least warmer now, in this room, I think, than it was when we first looked at the thermometer.’
‘That is true; but you have done something, Lucy, to the thermometer, that has made the quicksilver rise.’
‘I! — What have I done? — I have not even touched it!’
‘But you have put your face close to it, and your warm breath has warmed the glass. Now look, when I put my hand, which I have just warmed at the fire, upon the bottom of the thermometer — upon this little round ball, or bulb, where the greatest part of the quicksilver is — look, how it rises in the tube! and now I will carry the thermometer near the fire, and you will see how much more the quicksilver will rise.’
Lucy looked at it, and she saw, that the quicksilver rose in the thermometer, when it was brought near to the fire.
As Harry was putting it still closer to the fire, his father called to him, and begged, that he would take care and not to break the thermometer.
‘O yes, father, I will take care. If you will give me leave, now, I will put it into this kettle of water, which is on the fire, and see whether the water is boiling or not. If it is boiling, the quicksilver will rise to boiling water heat, will it not? — I will hold the thermometer by the string at the top, so I shall not burn my fingers.’
His father stood by, while Harry tried this experiment; and Lucy saw, that, when the water boiled, the quicksilver rose to boiling water heat; that is, to 212 degrees.
Then Harry carried the thermometer back again to the window, and left it to cool for some minutes; and they saw, that the quicksilver fell to the place where it had been when they first looked at the thermometer this morning; that is to say, to 47 degrees.
‘Now you see,’ said Harry, ‘the use of the thermometer. It shows exactly how hot or how cold it is.’
‘It measures the degrees of heat,’ said their father, ‘and the name thermometer means measurer of heat, from two Greek words ‘; thermo means heat, meter means measure, as you may observe in the words barometer, pyrometer, hygrometer, and many others.’
‘But why, father, does the quicksilver rise in the tube when it is hot, and fall when it is cold? I do not understand why,’ said Lucy.
‘That is a sensible question,’ said her father; ‘and I am not sure, that I can answer it so as to make you understand me. It has been found, from experience, my dear, that quicksilver expands; that is, spreads out — takes up more room — when it is heated, than when it is cold: and it always expands equally when it is in the same heat. So that, by knowing how much more room it takes up, for instance, when it is held near the fire, than it did when it was hanging in the window, we could know how much greater the heat is near the fire, than at the window — Do you understand me, Lucy, my dear?’
‘Yes, father, — I think I do. You say, that, when the quicksilver is heated, it — I forget the word—’
‘Expands,’ cried Harry.
‘Yes, expands — When quicksilver is heated, it expands, father.’
‘But what do you mean by expands, my little girl?’
‘It spreads out every way — its size increases — it takes up more room.’
‘Very well — And what then?’
‘Why then — as it expands when it is heated, people can tell, by seeing or measuring the size of the quicksilver, how hot it is.’
‘True — But how do you think they know exactly how much it increases in size or bulk, when it is heated to different degrees of heat? — How do they measure and see at once the measure of this?’
‘With a pair of compasses, father,’ said Lucy.
‘Look at this little ball, or globe of quicksilver,’ said her father, pointing to a little ball of quicksilver in the glass, at the bottom of the thermometer. ‘Would it not be difficult to measure this with a pair of compasses every time you apply heat to it?’
‘That would be difficult to be sure,’ said Lucy.
‘There must be some other way — Some way too that it can be measured, without taking the quicksilver out of the glass every time.’
‘I know the way!’ cried Harry.
‘Don’t speak — don’t tell her — let your sister think, and find out for herself. And now I must shave; and do not either of you talk to me, till I have done.’
Whilst her father was shaving, Lucy looked at the thermometer, and considered about it; and she observed, that the thin, tall line, or column of quicksilver, in the little glass tube, rose from the bulb, or globe of quicksilver, at the bottom of the thermometer — and, when she put her warm hand upon this bulb, the quicksilver rose in the tube.
‘I know it now!’ cried Lucy, ‘but I must not tell it, till father has done shaving, lest I should make him cut himself.’
As soon as father had done shaving, Lucy, who had stood patientl
y at his elbow, stretched out her hand, and put the thermometer before his eyes.
‘Here, father! now I will show you.’
‘Not so near, my dear — do not put it so close to my eyes; for I cannot see it, when it is held very near to me,’ said her father.
‘There, father; you can see it now,’ said Lucy, ‘cannot you? and you see the quicksilver, in this little glass globe, at the bottom of the thermometer.’
‘Yes; I see it,’ said her father.
‘When it is heated, and when it expands, continued Lucy, ‘it must have more room, and it cannot get out at the bottom, or sides, or any way, but up this little glass tube. There is an opening, you see, from the uppermost part of that little globe, into this glass tube.’
‘Very well,’ said her father — I go on, my dear.’
‘And, when the quicksilver is made hot, and hotter, it rises high, and higher, in this tube, because’ it wants more and more room; and the height it rises to, show how hot it is, because that is just the measure of how much the quicksilver has expanded — has grown larger. And, by the words that are written here — and by these little lines — these degrees, I believe, you call them — you can know, and tell people exactly how much the quicksilver rises or falls — and that shows how hot it is.’
‘Pretty well explained, Lucy — I think you understand it.’
‘But one thing she does not know,’ said Harry, ‘that, in making a thermometer, the air must be first driven out of the little tube, and the glass must be quite closed at both ends, so as to keep out the air. My uncle told me this — and now, father,’ continued Harry, ‘will you tell me something about the barometer — I know, that it is not the same as the thermometer; but I do not know the difference — Father, will you explain it to me?’
‘Not now — You have had quite enough for this morning, and so have I. I must make haste and finish dressing, and go to breakfast.’
Complete Novels of Maria Edgeworth Page 348
