Common Science.

by Carleton W. Washburne.

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 cla.s.sified according to the scientific principles needed in order to answer them. These principles const.i.tute 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 ma.s.s 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 cla.s.ses 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 quant.i.tative 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 a.s.sumption that scientific method can be taught to children by making them perform uninteresting, quant.i.tative 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 cla.s.ses, 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 a.s.surance 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 cla.s.ses 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 cla.s.s 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 subst.i.tuted 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 cla.s.s name the principles back of each example.

This course is so arranged that it can be used according to the regular cla.s.s 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 a.s.sistance 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 cla.s.s 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 cla.s.s work, also made a division into lessons impracticable. Each teacher will soon discover about how much matter her cla.s.s, if she uses the cla.s.s 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 gla.s.s 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 a.s.sistance in the cla.s.sification and selection of inferences. Miss Beatrice Harper a.s.sisted 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