From the Back Cover:
Using a fascinating technique Imelda and Robert Updegraff show the "changes" that happen to the enviroment and present them by means of exciting illustrations and lively, clear text. Each book in this unique series explains major subjects and a cross-referenced index links one title with the other provide a stimulating reference library for discovery and for topic work. There is a section of simple experiments which enable the reader to explore the working of the enviroment for him or herself using easily found materials.
Using a fascinating technique Imelda and Robert Updegraff show the "changes" that happen to the enviroment and present them by means of exciting illustrations and lively, clear text. Each book in this unique series explains major subjects and a cross-referenced index links one title with the other provide a stimulating reference library for discovery and for topic work. There is a section of simple experiments which enable the reader to explore the working of the enviroment for him or herself using easily found materials.