A laboratory course in physics of the household to accompany Lynde's Physics of the household

Front matter

GIFT OF Publisher

A LABORATORY COURSE IN PHYSICS OF THE HOUSEHOLD

THE MACMILLAN COMPANY

Preface

THIS Laboratory Course in Physics of the Household covers the ground recommended by the College Entrance Board. It differs from similar courses in four ways : first, it contains Exercises in addition to the usual Experiments ; second, it requires the use of the common weights and measures side by side with the metric weights and measures ; third, it permits the use of much apparatus familiar to the student; and fourth, it encourages the student to set up a laboratory in his own home.

The Exercises help the student to appreciate how physics is applied in his home and in his environment in general. The Exercises and Experiments together complement the classroom work.

The use of the common weights and measures in addition to the metric weights and measures is justified, in the writer's opinion, as follows. Since we require young students to take a laboratory course in physics in order that they may obtain knowledge which they will apply in everyday life, it seems wise to allow them to obtain this knowledge in terms of the units (foot, pound, B.T.U., etc.) which they must use when they so apply it. Furthermore, the writer, although a strong advocate of the metric system, believes that it is pedagogical] y unsound to try to teach physics by means of the metric system exclusively. It is an attempt to teach an unknown subject by means of an unknown system of weights and measures and it leads to confusion and lack of power on the part of the student. Long experience leads the writer to believe that the correct method is to introduce the subject by means of the common system and then to use the two systems side by side. This is the method followed in this book.

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VI PREFACE

There are three reasons why familiar apparatus (3-qt. pail, spring balance, common thermometer, etc.) is used. If the student uses apparatus with which he is familiar, he finds that he can make experiments at home and he learns that an experiment may be made when and where information is desired ; whereas, if he uses only the apparatus commonly found in a school, he is likely to get the impression that an experiment is something to be made only in the school laboratory. The familiar apparatus, moreover, allows a student to work with large quantities and thereby decreases the chances of error. Also the familiar apparatus is cheap and easy to obtain.

The reason for encouraging the student to set up a laboratory at home is obvious. If he plans his own experiments on a given subject and then makes these experiments, he gets a firmer grasp of the subject than if he makes only the experiments in school.

The apparatus required for these experiments (except for a few in electricity) is simple and inexpensive and much of it is similar to that now found in high school laboratories. It is advisable to have one set for each two students in order that the whole class may make the same experiment at the same time. Where only one or two sets can be purchased, however, the class may make the experiments in rotation.

For the convenience of those ordering apparatus, we give on pages 139-146 a list of the apparatus required, with the approximate cost, and also the names and addresses of a number of firms from which the apparatus may be purchased. The prices quoted are those in effect before the war. The present prices can be obtained by writing to any of the firms mentioned.

C. J. L.

Contents

PAGE

Introduction to the Students : APPARATUS FOR A HOME LABORATORY xi-xv

MECHANICS