“_Vacuum tubes_ are known as _valves_ in England. This is based on the fact that they can be used to control the flow of electricity, similar in concept to the way in which their mechanical namesakes are used to control the flow of fluids.” ElectricityWord Origins Book:Bebop to the Boolean Boogie: An Unconventional Guide to Electronics Source: Bebop to the Boolean Boogie: An Unconventional Guide to Electronics