In a hydraulic transmission line, the energy flows as mechanical waves through the water, but in an electric transmission line the energy flows as fields in the space surrounding the wires, and does not flow inside the metal.
U hidrauličkoj transmisionoj liniji energija teče kao mehanički talasi kroz vodu, ali u električnoj transmisionoj liniji energija teče kao polja u prostoru koji okružuje žice i ne teče u metalu.