Ed Sobey & Woody Sobey 
The Way Toys Work : The Science Behind the Magic 8 Ball, Etch A Sketch, Boomerang, and More [PDF ebook] 
The Science Behind the Magic 8 Ball, Etch A Sketch, Boomerang, and More

A Selection of the Scientific American Book Club Profiling 50 of the world’s most popular playthings–including their history, trivia, and the technology involved–this guide uncovers the hidden science of toys. Discover how an Etch A Sketch writes on its gray screen, why a boomerang returns after it is thrown, and how an RC car responds to a remote control device. Leaving no detail unrevealed, the guide includes original patent-application blueprints and photos of the ‘guts’ of several devices. Inventors and museum curators also offer their observations of favorite gizmos while dispelling (or confirming) several toy legends. Complete with explanations of do-it-yourself experiments and tips on reverse engineering old toys to observe their interior mechanics, this entertaining and informative reference even provides pointers on how budding toy makers can build their own toys using only recycled materials and a little ingenuity.