"Explains the principles of inventing and provides photo-illustrated instructions for making a variety of projects that harness energy"--Provided by publisher.
"Explains the principles of inventing and provides photo-illustrated instructions for making a variety of projects that recycle and reuse materials"--Provided by publisher.
Explains the principles of inventing and provides instructions for making a variety of structures and contraptions, including a trash grabber, an egg parachute, and a miniature bridge of toothpicks.
