Discusses how common household items can become useful inventions, how many inventions were discovered accidentally, and how new products can be patented.

Experimenting with Sound

by Robert Gardner

Published 1 October 1991
Explores the properties of sound through experiments and activities.

Discusses energy and its conservation and provides experiments with which to investigate the topic.

Human Evolution

by Robert Gardner

Published 1 October 1999
Traces past and present theories of human origins and development.