Postcard from 'Phi' [George Francis Fitzgerald], to O J [Oliver Joseph] Lodge, 2 Grove Park, Liverpool, and forwarded to [Joseph] Larmor, St John's College, Cambridge 'Preston has just been in with a splendid photograph of the tripling of the line (a cadmium one) and of its polarisation by the Zeeman action. He took it a few days ago with the big 20 foot grating at the Royal University'. 22 November 1897