How does a toilet flush? Find out with a pair of two-liter bottles and a length of rubber tubing. What about the fingers on your hand? Build a working model of its muscles, bones and tendons using drinking straws, craft sticks, tape, and string. These and dozens of other hands-on projects can be found in Stomp Rockets, Catapults, and Kaleidoscopes. Each device has been designed to use recycled or nearly free materials. Author Curt Gabrielson has created and refined toys and demonstrations that children will find exciting to construct and operate. Readers will get experience working with common tools and be encouraged to modifygauge and improve the designs. Each project includes materials and tools lists, step-by-step instructions with photographs, and a summary of the science concept being demonstrated. Teachers will also appreciate the optional follow-up questions to guage student understanding.