Diagrams, galvanometers by Thomas Gray and Andrew Gray Three pages of diagrams, labelled figures 1-3, showing a horizontal section of coils, a horse-shoe needle and a distributing plate for a galvanometer. Subject: Electricity / Scientific apparatus and equipment Prints of these diagrams were published in volume 36 of the Proceedings of the Royal Society alongside the paper 'On a new reflecting galvanometer of great sensibility, and on new forms of astatic galvanometers'. 1884