[mikethedruid]

Up until this century, virtually all house plumbing was done with either iron or copper piping. Many homes also used either hot water or steam heat with radiators. It was common to use a copper plated steel strap clamped around a radiator valve as your radio ground, or, to clamp the ground to one of the cold water pipes in the cellar. One could also buy ground rods from the hardware store, and drive them into the ground close to where your antenna lead would come into your house, and use that ground for the lightning arrestor as well as continuing on to the radio. My own outdoor antenna is connected just that way.