Sách nói: General Science

GENERAL SCIENCE
BY BERTHA M. CLARK, PH.D.
PREFACE
This book is not intended to prepare for college entrance examinations; it will not, in fact, prepare for any of the present-day stock examinations in physics, chemistry, or hygiene, but it should prepare the thoughtful reader to meet wisely and actively some of life's important problems, and should enable him to pass muster on the principles and theories underlying scientific, and therefore economic, management, whether in the shop or in the home. We hear a great deal about the conservation of our natural resources, such as forests and waterways; it is hoped that this book will show the vital importance of the conservation of human strength and health, and the irreparable loss to society of energy uselessly dissipated, either in idle worry or in aimless activity.