Chapter XV
., I told you about some seeds in which the life was asleep many hundred years. And it may be that the life might be kept asleep in frogs and other animals as long as this by steady cold. A toad was found lately in the middle of a tree fast asleep. How he came there was not known, but the wood had kept growing year after year, and as there were 67 rings outside of the toad, it was clear that he had been there 67 years. A long sleep it was, but he soon woke up and hopped about like other toads.
[Sidenote: The winter sleep of some animals not perfectly sound.]
There are some kinds of animals that crawl into winter quarters in whom life is not wholly asleep. The blood moves a little, and they once in a while take a breath; and, besides, they now and then, when the weather is quite warm, wake up enough to eat a little. Now it is curious that such animals always lay up something to eat right alongside of them when they go into their winter sleeping-places. But those who do not wake up at all do not lay up any food, for it would not be used if they did lay it up. They are governed by instinct in this matter.
The field-mouse lays up at its side nuts and grain when it goes into its winter quarters, and when it is partly waked up by a warm day, eats a little of his store. The bat does not lay up any thing, although he wakes up when it is warm. He does not need to lay up any thing, because the warmth that wakes him up wakes up also gnats and insects on which he lives. He catches some of these, and then, as he finds himself going to sleep again, he hangs himself up by his hooks as before. The marmot or woodchuck does not wake up at all, but he always lays up some dried grass in his hole. What is this for? He feeds on it when he first wakes up in the spring, to get a little strength before he comes out from his hole.
[Sidenote: How much life is asleep in the winter.]
How much life, then, is asleep in the winter in animals as well as in plants! And how busy is life in its waking in the spring! While the roots and seeds in the ground send up their shoots, and the sap again circulates in the trees and shrubs, and the buds swell, multitudes of animals are crawling out of their winter hiding-places into the warm, balmy air. And when the leaves are fully out, and the flowers abound, the earth swarms with the busy insects, and birds, and creeping things, of which we saw none during the winter.
[Sidenote: Flight of birds south in winter.]
Some of the birds that we see in the spring have not been asleep during the cold weather, but have spent their winter at the South, and have now winged their way back to spend their summer with us. They go back and forth in this way every year, guided by that wonderful and mysterious thing, instinct. How this makes them take their flight at the right time, and in the right direction, we do not understand.
_Questions._--Why do animals need sleep? Why do you feel tired after work, or play, or study? Why does the blood circulate and the breathing go on in sleep? When is most of the repairing of the body done? How is it with its growth? What is said about night as the time for sleep? Mention some animals that sleep in the day and are awake in the night. What is said about people that turn night into day? Why would not merely keeping the body still, without sleeping, answer for our rest? What is said about dreaming? What is said of the winter sleep of some animals? Tell about the frogs and the toad. Why do some animals take food into their winter sleeping-places? Tell about the field-mouse, the bat, and the marmot. What is said about the waking up of life in the spring in animals and in plants? What is said about the birds?
THE CHILD’S BOOK OF NATURE.
FOR THE USE OF
FAMILIES AND SCHOOLS.
INTENDED TO AID MOTHERS AND TEACHERS IN TRAINING CHILDREN
IN THE OBSERVATION OF NATURE.
IN THREE PARTS.
## PART III.--AIR, WATER, HEAT, LIGHT, &c.
BY WORTHINGTON HOOKER, M.D.,
AUTHOR OF “FIRST BOOK IN CHEMISTRY,” “CHEMISTRY,” “NATURAL PHILOSOPHY,” “NATURAL HISTORY,” ETC.
With Illustrations.
NEW YORK:
HARPER & BROTHERS, PUBLISHERS, FRANKLIN SQUARE.
1882.
By Dr. WORTHINGTON HOOKER.
THE CHILD’S BOOK OF NATURE. For the Use of Families and Schools; intended to aid Mothers and Teachers in training Children in the Observation of Nature. In three Parts. Illustrations. The Three Parts complete in one vol., Small 4to, Cloth, $1 00; Separately, Cloth, Part I., 40 cents; Parts II. and III., 44 cents each.
## PART I. PLANTS.--PART II. ANIMALS--PART III. AIR, WATER, HEAT, LIGHT,
&c.
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NATURAL HISTORY. For the Use of Schools and Families. Illustrated by nearly 300 Engravings. 12mo, Cloth, 90 cents.
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Entered, according to Act of Congress, in the year one thousand eight hundred and fifty-seven, by HARPER & BROTHERS, in the Clerk’s Office of the District Court of the Southern District Court of New York.
PREFACE.
There is no obvious connection between the subjects now to be considered and those which were presented in Parts First and Second. But, after looking at what is of interest in the plants and animals that live in air and water, it seems appropriate to pass to the examination of the phenomena that air and water themselves furnish to us. And then with these subjects are naturally associated the other subjects contained in this Part--light, heat, electricity, etc.
Let me not be understood to say that the subjects treated in this Part are entirely disconnected from those in the other two Parts. There are many points of connection, resulting from the dependence of life upon air, water, heat, etc., and also from the mechanical principles that are brought into operation in the living machinery of both plants and animals. Still, the connection is not of that obvious and intimate character which we see between the subjects of Parts First and Second.
I have placed these subjects last in the Child’s Book of Nature because they are not, for the most part, so easily understood as the subjects contained in the other Parts. The mind of the learner needs the training in observation and reasoning which it has in studying the phenomena of plants and animals to enable it to grasp all of the points which are here presented; and as in matter, so in style, I have supposed an advance of mental power in the learner. I have relaxed a little my strictness in simplicity. Indeed, I did so in a small degree in the Second Part. I have been careful, however, not to allow myself too much latitude in this respect, but have endeavored throughout to make the advance both in style and matter to correspond with the advance of mental capacity in the learner, and not go beyond it.
The subjects of this Part are those which are commonly ranged under the general term Natural Philosophy. They are not presented either formally or fully, but those points are selected which will interest a young beginner and be intelligible to him. I have made it an object to exclude all that are of a different character, for it is very important that the young learner should not be discouraged with difficulties and burdened with uninteresting matters at the outset.
It will be seen, however, that in making the selection alluded to, I have, after all, given quite a full view of the fundamental parts of the different subjects. The simple principles which form the basis of Natural Philosophy are most of them very fully illustrated. And I can not forbear remarking that many older scholars, who have pursued the study in the more formal manner common in our schools, might find their ideas rendered more clear and definite by looking at the simple views here presented.
I would call the attention of the teacher to one feature in my mode of developing scientific subjects to the young, which I deem to be of great importance. I observe a natural gradation in their development, beginning with the simplest views, and leading the learner gradually to those that are more complex and less easily understood. Not only is one thing given at a time, but each thing is put in its right place. I will cite a single example. Take what is said about air. First, the simple and single fact that it is a material thing is illustrated. This is followed by noticing what it does when in motion. Then I show how, by its resistance, birds and insects rise on the wing. Next I pass to the pressure of the air, first illustrating, in a simple way, the fact of its pressure in all directions, and then passing to show how its pressure operates in the pump and in the barometer. Then come illustrations of its pressure as exhibited in experiments with the air-pump, the immense pressure which the body sustains from it, and the manner in which it does this being especially noticed and explained. Next follows the elasticity of the air when compressed, illustrated by the operation of pop-guns, air-guns, etc. Then is illustrated the pressure of the air in making balloons, bubbles, and other light things rise in it. This leads naturally to the consideration of the rising of smoke and the operation of chimneys. And then, lastly, in the latter part of the book, the action of the attraction of gravitation upon the air is noticed, thus ultimately arriving at the real cause of most of the phenomena of the air’s pressure.
Another feature, to which I will barely allude, is a frequent reference to analogies. Thus, for example, in giving the facts about air, I point out the resemblance between flying and swimming, between the action of compressed air and that of compressed steam, and of the gases produced by burning powder, etc. This feature not only adds interest to the various subjects, but makes the points in hand more clear, and gives a wider range to the views of the learner.
It is the author’s intention to follow this with other books calculated to carry forward the scholar in his observation of nature. Indeed, I have already published two books, “First Book in Physiology” and “Human Physiology,” by which the scholar can proceed with the study of the subjects treated of in Part Second of this book; and as soon as I can do so, I shall write some books for the purpose of enabling him to go on with the study of the subjects treated of in the other Parts. The whole together will constitute to some extent a series of books on the sciences, adapted to the different degrees of advancement in the pupils.
It will be observed that in this Part there are many experiments spoken of. These the teacher should try before the pupils so far as is practicable. I have also made extensive use of common phenomena as illustrations of the points presented. This will tend to form in the scholar the habit of observing what is just around him--the common things, so much overlooked in education--a habit which is a never-failing source of information and enjoyment. And both teacher and scholar, if they catch the spirit which I have endeavored to infuse into the book, will from their own observation add to the illustrations that I have given, and thus materially increase the interest of the daily recitations.
WORTHINGTON HOOKER.
CONTENTS.
CHAPTER PAGE
I. AIR 9
II. AIR IN MOTION 13
III. FLYING AND SWIMMING 18
IV. THE PRESSURE OF THE AIR 25
V. PUMPS 30
VI. THE BAROMETER 36
VII. THE AIR-PUMP 39
VIII. GASES 44
IX. POWDER 48
X. POP-GUNS 53
XI. BALLOONS AND BUBBLES 57
XII. MORE ABOUT BALLOONS 63
XIII. HEATED AIR 68
XIV. CHIMNEYS 72
XV. USES OF WATER 77
XVI. WATER ALWAYS TRYING TO BE LEVEL 81
XVII. THE PRESSURE OF WATER 87
XVIII. ATTRACTION IN SOLIDS AND FLUIDS 92
XIX. WATER IN THE AIR 97
XX. CLOUDS 101
XXI. SNOW, FROST, AND ICE 105
XXII. HEAT AND COLD 110
XXIII. THE DIFFUSION OF HEAT 114
XXIV. WHAT HEAT DOES 120
XXV. STEAM 125
XXVI. LIGHT 130
XXVII. COLOR 135
XXVIII. MORE ABOUT COLOR 130
XXIX. ELECTRICITY 144
XXX. MORE ABOUT ELECTRICITY 150
XXXI. MAGNETISM 155
XXXII. GRAVITATION 159
XXXIII. THE MOTION OF THE EARTH 165
XXXIV. FRICTION 172
XXXV. CONCLUSION 176
THE
CHILD’S BOOK OF NATURE.
## PART III.--AIR, WATER, HEAT, LIGHT, ETC.
##