Origins of the equivalent circuit concept: the current-source equivalent

The voltage-source equivalent was first derived by Hermann von Helmholtz (1821-1894) in an 1853 paper. Exactly thirty years later in 1883, Leon Charles Thevenin (1857-1926) published the same result, apparently unaware of Helmholtz´s work. The generality of the equivalent source network was not appreciated until forty-three years later. Then, in 1926, Edward Lawry Norton (1898-1983) wrote an internal Bell Laboratory technical report that described in passing the usefulness in some applications of using the current-source form of the equivalent circuit. In that same year, Hans Ferdinand Mayer (1895-1980) published the same result and detailed it fully. As detailed subsequently, these people intertwine in interesting ways.