This book is a collection of 66 "How Things Work" columns from the journal "The Physics Teacher," 1983-1991. All the devices and phenomena are ones that are met in everyday life, involve physics principles, and require explanations that are not immediately obvious. Topics include: touch panels in elevators, liquid crystal displays, metal locators, automatic toasters, traffic signals, copy machines, smoke alarms, halogen lamps, maintenance-free car batteries, air bags, bar codes, hydraulic ram, wind chill factor, doppler radar, and fishing spinners. The text is illustrated with black and white photographs and diagrams. (PR)