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Disclaimer:
This is a work of historical interest only and much of the scientific
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Do not try this at home!
* * * * *
COMMON SCIENCE
NEW-WORLD SCIENCE SERIES
_Edited by John W. Ritchie_
* * * * *
SCIENCE FOR BEGINNERS
By _Delos Fall_
TREES, STARS, AND BIRDS
By _Edwin Lincoln Moseley_
COMMON SCIENCE
By _Carleton W. Washburne_
HUMAN PHYSIOLOGY
By _John W. Ritchie_
SANITATION AND PHYSIOLOGY
By _John W. Ritchie_
LABORATORY MANUAL FOR USE WITH "HUMAN PHYSIOLOGY"
By _Carl Hartman_
* * * * *
EXERCISE AND REVIEW BOOK IN BIOLOGY
By _J. G. Blaisdell_
PERSONAL HYGIENE AND HOME NURSING
By _Louisa C. Lippitt_
SCIENCE OF PLANT LIFE
By _Edgar Nelson Transeau_
* * * * *
ZOOeLOGY
By _T. D. A. Cockerell_
EXPERIMENTAL ORGANIC CHEMISTRY
By _Augustus P. West_
* * * * *
_NEW-WORLD SCIENCE SERIES_
_Edited by John W. Ritchie_
COMMON SCIENCE
_by_
_Carleton W. Washburne_
_Superintendent of Schools, Winnetka, Illinois_
_Formerly Supervisor in Physical Sciences and
Instructor in Educational Psychology_
_State Normal School_
_San Francisco, California_
_ILLUSTRATED_
WITH PHOTOGRAPHS AND
DRAWINGS
_Yonkers-on-Hudson, New York_
WORLD BOOK COMPANY
1921
WORLD BOOK COMPANY
THE HOUSE OF APPLIED KNOWLEDGE
Established, 1905, by Caspar W. Hodgson
YONKERS-ON-HUDSON, NEW YORK
2126 PRAIRIE AVENUE, CHICAGO
One of the results of the World War has been a widespread desire
to see the forces of science which proved so mighty in destruction
employed generally and systematically for the promotion of human
welfare. World Book Company, whose motto is The Application of the
World's Knowledge to the World's Needs, has been much in sympathy
with the movement to make science an integral part of our elementary
education, so that all our people from the highest to the lowest will
be able to use it for themselves and to appreciate the possibilities
of ameliorating the conditions of human life by its application to the
problems that confront us. We count it our good fortune, therefore,
that we are able at this time to offer _Common Science_ to the
schools. It is one of the new type of texts that are built on
educational research and not by guess, and we believe it to be a
substantial contribution to the teaching of the subject
NWSS:WCS-2
Copyright, 1920, by World Book Company
Copyright in Great Britain
_All rights reserved_
PREFACE
A collection of about 2000 questions asked by children forms the
foundation on which this book is built. Rather than decide what it is
that children ought to know, or what knowledge could best be fitted
into some educational theory, an attempt was made to find out what
children want to know. The obvious way to discover this was to let
them ask questions.
The questions collected were asked by several hundred children in the
upper elementary grades, over a period of a year and a half. They
were then sorted and classified according to the scientific principles
needed in order to answer them. These principles constitute the
skeleton of this course. The questions gave a very fair indication of
the parts of science in which children are most interested.
Physics, in simple, qualitative form,--not mathematical physics, of
course,--comes first; astronomy next; chemistry, geology, and certain
forms of physical geography (weather, volcanoes, earthquakes, etc.)
come third; biology, with physiology and hygiene, is a close fourth;
and nature study, in the ordinary school sense of the term, comes in
hardly at all.
The chapter headings of this book might indicate that the course
has to do with physics and chemistry only. This is because general
physical and chemical principles form a unifying and inclusive matrix
for the mass of applications. But the examples and descriptions
throughout the book include physical geography and the life sciences.
Descriptive astronomy and geology have, however, been omitted. These
two subjects can be best grasped in a reading course and field trips,
and they have been incorporated in separate books.
The best method of presenting the principles to the children was the
next problem. The study of the questions asked had shown that the
children's interests were centered in the explanation of a wide
variety of familiar facts in the world about them. It seemed evident,
therefore, that a presentation of the principles that would answer
the questions asked would be most interesting to the child. Experience
with many different classes had shown that it is not necessary to
subordinate these explanations of what children really wish to know to
other methods of instruction of doubtful interest value.
Obviously the quantitative methods of the high school and college were
unsuitable for pupils of this age. We want children to be attracted to
science, not repelled by it. The assumption that scientific method
can be taught to children by making them perform uninteresting,
quantitative experiments in an effort to get a result that will tally
with that given in the textbook is so palpably unfounded that it
is scarcely necessary to prove its failure by pointing to the very
unscientific product of most of our high school science laboratories.
After a good deal of experimenting with children in a number of
science classes, the method followed in this book was developed.
Briefly, it is as follows:
At the head of each section are several of the questions which, in
part, prompted the writing of the section. The purpose of these is to
let the children know definitely what their goal is when they begin a
section. The fact that the questions had their origin in the minds
of children gives reasonable assurance that they will to some extent
appeal to children. These questions in effect state the problems which
the section helps to solve.
Following the questions are some introductory paragraphs for arousing
interest in the problem at hand,--for motivating the child further.
These paragraphs are frequently a narrative description containing a
good many dramatic elements, and are written in conversational style.
The purpose is to awaken the child's imagination and to make clear the
intimate part which the principle under consideration plays in his own
life. When a principle is universal, like gravity, it is best brought
out by imagining what would happen if it ceased to exist. If a
principle is particular to certain substances, like elasticity, it
sometimes can be brought out vividly by imagining what would happen if
it were universal. Contrast is essential to consciousness. To contrast
a condition that is very common with an imagined condition that is
different brings the former into vivid consciousness. Incidentally, it
arouses real interest. The story-like introduction to many sections is
not a sugar coating to make the child swallow a bitter pill. It is
a psychologically sound method of bringing out the essential and
dramatic features of a principle which is in itself interesting, once
the child has grasped it.
Another means for motivating the work in certain cases consists
in first doing a dramatic experiment that will arouse the pupil's
interest and curiosity. Still another consists in merely calling the
child's attention to the practical value of the principle.
Following these various means for getting the pupil's interest, there
are usually some experiments designed to help him solve his problem.
The experiments are made as simple and interesting as possible. They
usually require very inexpensive apparatus and are chosen or invented
both for their interest value and their content value.
With an explanation of the experiments and the questions that arise,
a principle is made clear. Then the pupil is given an opportunity to
apply the principle in making intelligible some common fact, if the
principle has only intelligence value; or he is asked to apply the
principle to the solution of a practical problem where the principle
also has utility value.
The "inference exercises" which follow each section after the first
two consist of statements of well-known facts explainable in terms
of some of the principles which precede them. They involve a constant
review of the work which has gone before, a review which nevertheless
is new work--they review the principles by giving them new
applications. Furthermore, they give the pupil very definite training
in explaining the common things around him.
For four years a mimeographed edition of this book has been used in
the elementary department of the San Francisco State Normal School.
During that time various normal students have tried it in public
school classes in and around San Francisco and Oakland, and it has
recently been used in Winnetka, Illinois. It has been twice revised
throughout in response to needs shown by this use.
The book has proved itself adaptable to either an individual system of
instruction or the usual class methods.
TO THE TEACHER
Do not test the children on the narrative description which introduces
most sections, nor require them to recite on it. It is there merely to
arouse their interest, and that is likely to be checked if they think
it is a lesson to be learned. It is not at all necessary for them
to know everything in the introductory parts of each section. If the
children are interested, they will remember what is valuable to
them; if they are not, do not prolong the agony. The questions which
accompany and follow the experiments, the applications or required
explanations at the ends of the sections, and the extensive inference
exercises, form an ample test of the child's grasp of the principles
under discussion.
It is not necessary to have the children write up their experiments.
The experiments are a means to an end. The end is the application
of the principles to everyday facts. If the children can make these
applications, it does not matter how much of the actual experiments
they remember.
If possible, the experiments should be done by the pupils individually
or in couples, in a school laboratory. Where this cannot be done,
almost all the experiments can be demonstrated from the teacher's desk
if electricity, water, and gas are to be had. Alcohol lamps can be
substituted for gas, but they are less satisfactory.
It is a good plan to have pupils report additional exemplifications
of each principle from their home or play life, and in a quick oral
review to let the rest of the class name the principles back of each
example.
This course is so arranged that it can be used according to the
regular class system of instruction, or according to the individual
system where each child does his own work at his natural rate of
progress. The children can carry on the work with almost no assistance
from the teacher, if provision is made for their doing the experiments
themselves and for their writing the answers to the inference
exercises. When the individual system is used, the children may write
the inference exercises, or they may use them as a basis for study
and recite only a few to the teacher by way of test. In the elementary
department of the San Francisco State Normal School, where the
individual system is used, the latter method is in operation. The
teacher has a card for each pupil, each card containing a mimeographed
list of the principles, with a blank after each. Whenever a pupil
correctly explains an example, a figure 1 is placed in the blank
following that principle; when he misapplies a principle, or fails to
apply it, an _x_ is placed after it. When there are four successive
1's after any principle, the teacher no longer includes that principle
in testing that child. In this way the number of inference exercises
on which she hears any one individual recite is greatly reduced.
This plan would probably have to be altered in order to adapt it to
particular conditions.
The Socratic method can be employed to great advantage in handling
difficult inferences. The children discuss in class the principle
under which an inference comes, and the teacher guides the discussion,
when necessary, by skillfully placed questions designed to bring the
essential problems into relief.[1]
[Footnote 1: At the California State Normal School in San Francisco,
this course in general science is usually preceded by one in
"introductory science."]
The chapters and sections in this book are not of even length. In
order to preserve the unity of subject matter, it was felt desirable
to divide the book according to subjects rather than according to
daily lessons. The varying lengths of recitation periods in different
schools, and the adaptation of the course to individual instruction
as well as to class work, also made a division into lessons
impracticable. Each teacher will soon discover about how much matter
her class, if she uses the class method, can take each day. Probably
the average section will require about 2 days to cover; the longest
sections, 5 days. The entire course should easily be covered in one
year with recitations of about 25 minutes daily. Two 50-minute periods
a week give a better division of time and also ought to finish the
course in a year. Under the individual system, the slowest diligent
children finish in 7 or 8 school months, working 4 half-hours weekly.
The fastest do it in about one third that time.
Upon receipt of 20 cents, the publishers will send a manual prepared
by the author, containing full instructions as to the organization and
equipment of the laboratory or demonstration desk, complete lists of
apparatus and material needed, and directions for the construction of
a chemical laboratory.
The latter is a laboratory course in which the children are
turned loose among all sorts of interesting materials and
apparatus,--kaleidoscope, microscope, electric bell, toy
motor, chemicals that effervesce or change color when put
together, soft glass tubing to mold and blow, etc. The teacher
demonstrates various experiments from time to time to show the
children what can be done with these things, but the children
are left free to investigate to their heart's content. There
is no teaching in this introductory course other than brief
answers to questions. The astronomy and geology reading
usually accompany the work in introductory science.
ACKNOWLEDGMENTS
To Frederic Burk, president of the San Francisco State Normal School,
I am most under obligation in connection with the preparation of this
book. His ideas inspired it, and his dynamic criticism did much toward
shaping it. My wife, Heluiz Chandler Washburne, gave invaluable help
throughout the work, especially in the present revision of the course.
One of my co-workers on the Normal School faculty, Miss Louise Mohr,
rendered much assistance in the classification and selection of
inferences. Miss Beatrice Harper assisted in the preparation of the
tables of supplies and apparatus, published in the manual to accompany
this book. And I wish to thank the children of the Normal School for
their patience and cooperation in posing for the photographs. The
photographs are by Joseph Marron.
CONTENTS
CHAPTER PAGE
1. GRAVITATION 1
1. A real place where things weigh nothing and
where there is no up or down 1
2. "Water seeks its own level" 6
3. The sea of compressed air in which we live:
Air pressure 10
4. Sinking and floating: Displacement 23
5. How things are kept from toppling over:
Stability 29
2. MOLECULAR ATTRACTION 36
6. How liquids are absorbed: Capillary attraction 36
7. How things stick to one another: Adhesion 41
8. The force that makes a thing hold together:
Cohesion 44
9. Friction 49
3. CONSERVATION OF ENERGY 57
10. Levers 57
11. Inertia 66
12. Centrifugal force 72
13. Action and reaction 77
14. Elasticity 82
4. HEAT 88
15. Heat makes things expand 88
16. Cooling from expansion 94
17. Freezing and melting 96
18. Evaporation 100
19. Boiling and condensing 107
20. Conduction of heat and convection 116
5. RADIANT HEAT AND LIGHT 122
21. How heat gets here from the sun; why things
glow when they become very hot 122
22. Reflection 129
23. The bending of light: Refraction 136
24. Focus 142
25. Magnification 150
26. Scattering of light: Diffusion of light 158
27. Color 161
6. SOUND 174
28. What sound is 174
29. Echoes 183
30. Pitch 185
7. MAGNETISM AND ELECTRICITY 190
31. Magnets; the compass 190
32. Static electricity 196
8. ELECTRICITY 203
33. Making electricity flow 203
34. Conduction of electricity 213
35. Complete circuits 219
36. Grounded circuits 225
37. Resistance 229
38. The electric arc 233
39. Short circuits and fuses 240
40. Electromagnets 247
9. MINGLING OF MOLECULES 259
41. Solutions and emulsions 259
42. Crystals 265
43. Diffusion 268
44. Clouds, rain, and dew: Humidity 274
45. Softening due to oil or water 290
10. CHEMICAL CHANGE AND ENERGY 293
46. What things are made of: Elements 293
47. Burning: Oxidation 312
48. Chemical change caused by heat 323
49. Chemical change caused by light 326
50. Chemical change caused by electricity 335
51. Chemical change releases energy 340
52. Explosions 342
11. SOLUTION AND CHEMICAL ACTION 349
53. Chemical change helped by solution 349
54. Acids 351
55. Bases 355
56. Neutralization 360
57. Effervescence 365
12. ANALYSIS 370
58. Analysis 370
APPENDIXES:
A. The Electrical Apparatus 379
B. Construction of the Cigar-box Telegraph 381
INDEX 383
COMMON SCIENCE
CHAPTER ONE
GRAVITATION
SECTION 1. _A real place where things weigh nothing and where there is
no up or down._
Why is it that the oceans do not flow off the earth?
What is gravity?
What is "down," and what is "up"?
There is a place where nothing has weight; where there is no "up" or
"down"; where nothing ever falls; and where, if people were there,
they would float about with their heads pointing in all directions.
This is not a fairy tale; every word of it is scientifically true. If
we had some way of flying straight toward the sun about 160,000 miles,
we should really reach this strange place.
Let us pretend that we can do it. Suppose we have built a machine that
can fly far out from the earth through space (of course no one has
really ever invented such a machine). And since the place is far
beyond the air that surrounds the earth, let us imagine that we have
fitted out the air-tight cabin of our machine with plenty of air to
breathe, and with food and everything we need for living. We shall
picture it something like the cabin of an ocean steamer. And let us
pretend that we have just arrived at the place where things weigh
nothing:
When you try to walk, you glide toward the ceiling of the cabin and
do not stop before your head bumps against it. If you push on the
ceiling, you float back toward the floor. But you cannot tell whether
the floor is above or below, because you have no idea as to which way
is up and which way is down.
As a matter of fact there is no up or down. You discover this quickly
enough when you try to pour a glass of water. You do not know where
to hold the glass or where to hold the pitcher. No matter how you hold
them, the water will not pour--point the top of the pitcher toward the
ceiling, or the floor, or the wall, it makes no difference. Finally
you have to put your hand into the pitcher and pull the water out.
It comes. Not a drop runs between your fingers--which way can it run,
since there is no down? The big lump of water stays right on your
hand. This surprises you so much that you let go of the pitcher. Never
mind; the pitcher stays poised in mid-air. But how are you going
to get a drink? It does not seem reasonable to try to drink a large
_lump_ of water. Yet when you hold the lump to your lips and suck it
you can draw the water into your mouth, and it is as wet as ever; then
you can force it on down to (or rather _toward_) your throat with your
tongue. Still you have left in your hand a big piece of water that
will not flow off. You throw it away, and it sails through the air of
the cabin in a straight line until it splashes against the wall. It
wets the wall as much as water on the earth would, but it does not run
off. It sticks there, like a splash-shaped piece of clear, colorless
gelatin.
Suppose that for the sake of experimenting you have brought an
elephant along on this trip. You can move under him (or over
him--anyway between him and the floor), brace your feet on the floor,
and give him a push. (If he happens to step on your toes while you are
doing this, you do not mind in the least, because he does not weigh
anything, you know.) If you push hard enough to get the elephant
started, he rises slowly toward the ceiling. When he objects on the
way, and struggles and kicks and tries to get back to the floor, it
does not help him at all. His bulky, kicking body floats steadily on
till it crashes into the ceiling.
No chairs or beds are needed in this place. You can lie or sit in
mid-air, or cling to a fixture on a wall, resting as gently there as
a feather might. There is no need to set the table for meals--just lay
the dishes with the food on them in space and they stay there. If the
top of your cup of chocolate is toward the ceiling, and your plate of
food is turned the other way, no harm is done. Your feet may happen
to point toward the ceiling, while some one else's point toward the
floor, as you sit in mid-air, eating. There is some difficulty in
getting the food on the dishes, so probably you do not wish to bother
with dishes, after all. Do you want some mashed potatoes? All right,
here it is--and the cook jerks the spoon away from the potatoes,
leaving them floating before you, ready to eat.
It is literally a topsy-turvy place.
Do you want to know why all this would happen? Here is the reason:
There is a great force known as _gravitation_. It is the pull that
everything in the universe has on everything else. The more massive a
thing is, the more gravitational pull it has on other objects; but the
farther apart things are, the less pull they have on each other.
The earth is very massive, and we live right on its surface; so it
pulls us strongly toward it. Therefore we say that we weigh something.
And since every time we roll off a bed, for instance, or jump off a
chair, the earth pulls us swiftly toward it, we say that the earth is
down. "Down" simply means toward the thing that is pulling us. If we
were on the surface of the moon, the moon would pull us. "Down" would
then be under our feet or toward the center of the moon, and the earth
would be seen floating up in the sky. For "up" means _away from_ the
thing which is pulling us.
WHY WATER DOES NOT FLOW OFF THE EARTH. It was because people did not
know about gravitation that they laughed at Columbus when he said the
earth was round. "Why, if the earth were round," they argued, "the
water would all flow off on the other side." They did not know that
water flows downhill because the earth is pulling it toward its center
by gravitation, and that it does not make the slightest difference on
which side of the earth water is, since it is still pulled toward the
center.
WHY THE WORLD DOES NOT FALL DOWN. And people used to wonder "what held
the earth up." The answer, as you can see, is easy. There simply is no
up or down in space. The earth cannot fall down, because there is no
down to fall to. "Down" merely means toward the earth, and the earth
cannot very well fall toward itself, can it? The sun is pulling on it,
though; so the earth could fall into the sun, and it would do so, if
it were not swinging around the sun so fast. You will see how this
keeps it from falling into the sun when you come to the section on
centrifugal force.
WHY THERE IS A PLACE WHERE THINGS WEIGH NOTHING. Now about the place
where gravitation has no effect. Since an object near the sun is
pulled more by the sun than it is by the earth, and since down here
near the earth an object is pulled harder by the earth than by the
sun, it is clear that there must be a place between the sun and the
earth where their pulls just balance; and where the sun pulls just as
hard one way as the earth pulls the other way, things will not fall
either way, but will float. The place where the pulls of the sun and
the earth are equal is not halfway between the earth and the sun,
because the sun is so much larger and pulls so much more powerfully
than the earth, that the place where their pulls balance is much
nearer the earth than it is to the sun. As a matter of fact, it can be
easily calculated that this spot is somewhere near 160,000 miles from
the earth.
There are other spots like it between every two stars, and in the
center of the earth, and in the center of every other body. You see,
in the center of the earth there is just as much of the earth pulling
one way as there is pulling the other, so again there is no up or
down.
_APPLICATION 1._ Explain why the people on the other side of
the earth do not fall off; why you have weight; why rivers run
downhill; why the world does not fall down.