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 un- 

 suited 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 



3G0474 



