The wire fixtures shown are the old style, non-insulated, bare wire type that depended on the physical separation of the two current carrying wires to prevent short circuits. Prior to the 1930s, asbestos was the only durably and flexible insulating covering and it was expensive so instead, most just used bare wire put up out of the way. Usually you would find each wire ran down opposite sides of a joist.
December 4, 2012 at 8:07 pm
The wire fixtures shown are the old style, non-insulated, bare wire type that depended on the physical separation of the two current carrying wires to prevent short circuits. Prior to the 1930s, asbestos was the only durably and flexible insulating covering and it was expensive so instead, most just used bare wire put up out of the way. Usually you would find each wire ran down opposite sides of a joist.