e kids aged 9 to 14, it's the perfect eco-friendly building material, and Cardboard Box Engineering is the perfect guide to get them started on inventive tinkering. A working kaleidoscope, a marble roller coaster, a robotic hand, and a wind-powered tractor with cardboard gears are just some of the ingenious projects developed by Jonathan Adolph, author of the best-selling Mason Jar Science. Working with simple household tools, kids can follow the step-by-step photographic instructions to exercise their design smarts, expand their 3-D thinking, and learn the basics of physics and engineering with activities that have real-life applications.