GENERAL SCIENCE
BY
BERTHA M. CLARK, PH.D.
HEAD OF THE SCIENCE DEPARTMENT
WILLIAM PENN HIGH SCHOOL FOR GIRLS, PHILADELPHIA
NEW YORK - CINCINNATI - CHICAGO
AMERICAN BOOK COMPANY
1912
PREFACE
This book is not intended to prepare for college entranceexaminations; it will not, in fact, prepare for any of the present-daystock examinations in physics, chemistry, or hygiene, but it shouldprepare the thoughtful reader to meet wisely and actively some oflife's important problems, and should enable him to pass muster on theprinciples 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 showthe 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. Most of us would reproachourselves for lack of shrewdness if we spent for any article more thanit was worth, yet few of us consider that we daily expend on domesticand business tasks an amount of energy far in excess of that actuallyrequired. The farmer who flails his grain instead of threshing itwastes time and energy; the housewife who washes with her hands aloneand does not aid herself by the use of washing machine and properbleaching agents dissipates energy sadly needed for other duties.
The Chapter on machines is intended not only as a stimulus to theinvention of further labor-saving devices, but also as an eye openerto those who, in the future struggle for existence, must perforce goto the wall unless they understand how to make use of contrivanceswhereby man's limited physical strength is made effective for largertasks.
The Chapter on musical instruments is more detailed than seemswarranted at first sight; but interest in orchestral instruments isreal and general, and there is a persistent desire for intelligentinformation relative to musical instruments. The child of the laboreras well as the child of the merchant finds it possible to attend someof the weekly orchestral concerts, with their tiers of cheap seats,and nothing adds more to the enjoyment and instruction of such hoursthan an intimate acquaintance with the leading instruments. Unlessthis is given in the public schools, a large percentage of mankind isdeprived of it, and it is for this reason that so large a share of thetreatment of sound has been devoted to musical instruments.
The treatment of electricity is more theoretical than that used inpreceding Chapters, but the subject does not lend itself readily topopular presentation; and, moreover, it is assumed that theinformation and training acquired in the previous work will give thepupil power to understand the more advanced thought and method.
The real value of a book depends not so much upon the informationgiven as upon the permanent interest stimulated and the initiativearoused. The youthful mind, and indeed the average adult mind as [5] well, is singularly non-logical and incapable of continuedconcentration, and loses