This book is divided into chapters based on the general subjects of mechanics, air power, water power, electricity and magnetism, chemistry, acoustics, and optics. Each chapter includes groups of projects designed to teach specific scientific ideas within the general subject. Some projects include a section that allows students to try different variations on the original activity. Explanations are provided at the end of each group of projects. Many of the activities in this book can serve as the starting point for a science fair project. Projects include: Desktop Lever, Flip Game, Balancer, Broomstick Pulley, Spool Pulley, Rubber-Band Walker, Roll-Back Can, Mousetrap Car, Rocket Boat, Horizontal Rocket, Vertical Rocket, Two-Stage Rocket, Sailboat, Paper Plane, Paper-Plate Flyer, Sled Kite, Air Pump, Can Crusher, Hot-Air Balloon, Water Rocket, Waterwheel, Cartesian Driver, Boat, Water Clock, Coordination Tester, Doorbell, Lemon Light, Electromagnet, Compass, Glue, Coin Cleaner, Electrochemical Plating Machine, Kodak Cannon, Cold Pack, Cabbage Juice Indicator, Yogurt Cup Phones, Tin Can Howler, Funnel Stethoscope, Whistle, Paper Tube Kazoo, Guitar, Kaleidoscope, Periscope, Fun House Mirror, Shoe Box Camera, Thaumatrope, and Flip Book. (JRH)