Diagrams, experimental equipment and measurements by A W [Arthur William] Rucker Three diagrams, labelled figures 1-3, showing an apparatus for measuring magnetic permeability, an electromagnetic coil and a schematic of the 'magnetic floor' as observed by Rucker. Each diagram has a corresponding engraved print. Subject: Magnetism The prints were published in volume 48 of the Proceedings of the Royal Society alongside the paper 'On the relation between the magnetic permeability of rocks and regional magnetic disturbances'. 1890