How it Works

Steam engines, telephones and cameras become lessons in basic physics in Archibald Williams's illustrated guide. Written for readers curious about everyday machinery, How it Works explains steam, electricity, light, sound and the movement of water through familiar devices. Williams gives machine parts their technical names while using plain explanations and labelled diagrams to show how the parts fit together. His opening account follows the change from water to steam and the pressure that drives a piston.

Later chapters connect these principles with railway signals, musical instruments, pumps, clocks and other apparatus. The section on lenses explains how the distance between an object and a lens changes the position and size of its image, then relates that explanation to photography. Comparisons between the eye and a camera, or the heart and a pump, extend the mechanical approach to the body. Readers interested in older technology can use the book to see how physical principles were taught through the equipment of daily life.