The book proceding this one, Experiments in Science, was excellent Junior High science material, weak on organization, haphazard in arrangement. This book, devoted as it is to one phase -- electricity-is orderly in progression according to difficulty, as the young experimenter masters the techniques and principles involved at each stage. He learns how to make practical electrical devices, and electrical jokes (dear to a ten to twelve year old) as well. The boy who gets hold of this book is lost and his mother might as well resign herself to flashing lights, yards of copper wire, elaborate room-to-room telephone systems; while Dad may find his chair wired for sound. But it is good safe fun, and provides help for the boy with home-made equipment and some knowledge. Directions are clear- there are diagrams and lists of necessary equipment. Good.