In the fourth grade book of the series, the chapters get more interesting and more hands on. There is a flow to the chapters that begin with the natural world, to the past, to the present, then from the physical properties of our world to beyond Earth (the moon), then back to nature. It finishes with a chapter about the balance of nature and how man 'unbalances' it. Finally, a chapter on human beings and their senses.
The explanations of electricity and how to construct an electrical circuit are comprehensible and useful. There are plenty of demonstrations that the children can do themselves to show how electricity and light works. The drawings and diagrams are straightforward. Of course, it is not at all up to date: no one had attempted a moon flight yet, so not sure how accurate the information about the moon actually is. Nevertheless, I enjoyed reading this. ( )