Science plays a big role in how we create and use the tools and machines that help us in our daily lives. Scientific principles can be found at work in everything from the simplest hammer to the complex robotic devices found in modern factories. Tools and Machines describes when humans first started using tools and traces the evolution of tools from simple stone implements to the high-tech devices of today. Filled with full-color photographs and illustrations, this volume also features simple experiments that clearly illustrate these science concepts for readers.