Diagrams, experimental equipment and results by W H [William Henry] Preece Three diagrams, labelled figures 1-3. Figure 1 shows a cable connected to an electric coil while figures 2-3 show graphs relating to the results of Preece's experiments made using different types of wires, including copper, platinum, German silver and Swedish wrought iron. Subject: Electricity These diagrams were published in volume 36 of the Proceedings of the Royal Society alongside the paper 'On the heating effects of electric currents'. 1884