Laboratory lessons in general science

Preface

This set of laboratory exercises in general science is an outgrowth of courses given by the author in methods of teaching secondary school sciences. Some of the lessons represent the combined efforts of a class upon an assigned topic, but so reshaped that credit to any individual is out of question. Free use has been made of material from the author's Lessons in Astronomy, Chemistry, Nature Study, and Physics — manuals prepared for his own class work. Many of the exercises have enough material for more than one lesson, and should be subdivided to suit teaching conditions.

The preparation of these lessons was stimulated by the belief that one chief cause of failure to get desired results with beginning classes in the high school sciences lay in the character of the material chosen. It was believed possible to bring together from scattered sources that which would appeal to beginners and which would find its unity in their life experiences and interests. This involved the rejection of much material of great worth from the differentiated high school sciences that is unsuited for an elementary course. Teachers subject to the exactions of schoolroom service do not have the time to make selections of material and properly to relate and adapt them for use.

The fund of life experiences available for a laboratory course about which science instruction of a general and vi PREFACE

elementary nature may center is large and should be more freely used by science teachers in secondary schools. These life experiences, supplemented by the experimental knowledge gained under direction in school, makes possible a fuller understanding of the teachings of books and a ready acquisition and grouping of a wide range of facts.

The emphasis placed in these lessons upon the interests of the individual, in both their personal and their community aspects, is expression of a conviction on the part of the author that topics of social science should not only be included in a general science course but should be treated in much the same w^ay as are topics from the various fields of the natural sciences. Any unification of life interests and life problems with the spirit and procedure in science studies not only enriches the science teaching but reacts upon the daily living to make it more sane and more wisely ordered.

School work that requires discrimination in the importance of the facts involved in the affairs of life, that notes the bearing of these facts upon the well-being of the individual, and that formulates a rational course of action, not only develops a scientific attitude but it constitutes a training of inestimable worth in the education of youth. The varied interests of pupils are thus made centers about which to group newly acquired knowledge.

It is the author's belief that differentiation between the various sciences may be disregarded during the first year in high school. Emphasis is placed instead upon an interpretation of related scientific phenomena regardless of the fields into which any inquiry may lead. The relationship and unity indispensable in science studies is secured through a grouping of the interests and experiences of the

PREFACE Vll

pupils rather than in the principles and laws of any branch of science. And it has been the aim to select as material for study not only that which is valuable in itself but that which at the same time is likely to be a stimulus in a truly educative process.

The author wishes to express his appreciation of the helpful suggestions and criticisms coming from those who have read the manuscript of these lessons. He desires especially to thank Professor George E. Martin, Head of the Department of English in the State Normal School at Kearney ; and Dr. R. J. Pool, Professor of Botany in the State University at Lincoln. He is greatly indebted, too, for helpful suggestions from the following who have read portions of the manuscript : Miss Alice Loomis, Head of the Department of Home Economics at the State University of Nebraska; George E. Loveland, Professor of Meteorology in the State University and Director of the U. S. Weather Bureau; Dean E. L. Rouse, Superintendent of Practice in the State Normal School at Peru; Professor H. C. Filley, Head of the Department of Farm Management in the College of Agriculture ; and Professor B. C. Hendricks of the Department of Physics in the State Normal School at Peru.

HERBERT BROWNELL.

Lincoln, Nebraska. 1916.