This book is intended to serve as a source of ideas for devising simple scientific activities, investigations, and experiments and for the construction of necessary equipment using available materials. This revision of an earlier edition reflects modern approaches to science teaching at the elementary and secondary school levels. This edition has been enlarged with an expanded section in the biological sciences with new material in the earth and space sciences. The physical science section has added more chemistry teaching material. An index has also been included to provide greater ease in using the source book. (Author/LS)