This title comes with 20 easy-to-do experiments and 300 exciting pictures. It tells the story of technology, from simple gears and levers to high-tech gadgets and gizmos. It covers all the basics of how things work - with fascinating photographs of machines in action, plus accessible inside-view diagrams. Practical projects help you to make your own minimachines, including a windmill and a vacuum cleaner! It is ideal for 8- to 12-year-olds, for home and school use. The screw, the wedge, the lever and the sloping ramp are the foundations of much more complicated machines. This book explains how they work, and how they have contributed to technological progress over thousands of years. It investigates all kinds of devices - from a pair of pliers, to cranes, wind turbines and power drills - right down to the basics of how they operate. And by making their own levers, pulleys, belt drives, wheels and more, young readers will be able to look at the working world around them with a fresh awareness.