Armstrong effect

The Armstrong effect is the physical process by which static electricity is produced by the friction of a fluid. It was first discovered in 1840 when an electrical spark resulted from water droplets being swept out by escaping steam from a boiler. The effect is named after William Armstrong, who later became 1st Baron Armstrong, who was one of several people involved in discovering the effect and investigating the processes involved. Using this principle Armstrong went on to invent what he called the Armstrong Hydroelectric Machine, which, despite its name, generated static electricity and not hydroelectric power.