Diagrams, experimental equipment and results by Philip Cardew and Ralph Bagnold Three diagrams, labelled figures 1-3, showing a circuit diagram, a cross-section of experimental equipment and a graph labelled 'Curves of fall of potential'. Subject: Physics / Electricity A version of this paper was published in volume 56 of the Proceedings of the Royal Society as 'On the difference of potential that may be established at the surface of the ground immediately above and at various distances from a buried mass of metal charge from a high pressure electric light supply'. 1894