Publisher's Synopsis
One of a series which introduces young children to simple tools and how they work, this book explains the scientific principles of wheels and gives illustrated examples of everyday implements that employ these principles.;It also gives step-by-step instructions on how to make a working model that uses the principles explained such as a push-along tortoise that runs on wheels. As the book progresses through the elements of movement the tortoise develops from wheels to axles, the body, the nodding head, up and down movements and the different variations of movement.
