A diagram of the wiring within a trolley car. The trolley wheel (b) is held in a harp that is attached to a trolley pole (c). The other end of the trolley pole fits into a socket (d) and trolley base (e). (F) indicates where one end of the trolley wiring is, which passes through hood switches (g and h) and a fuse box (j). The wire is then spliced to another wire (l) that runs to the trolley posts in the two controllers. (K) is a lightning arrester.
International Correspondence Schools A Textbook on Electric Lighting and Railways (Scranton, PA: International Textbook Company, 1901)