Electron diffraction camera, c 1927.

Made by GP Thomson (1892-1975) of Aberdeen, the son of JJ Thomson (1856-1940) who identified the electron. Working in the same field, GP Thomson observed electron diffraction of electrons pasing through thin gold foil, recorded on photographic plates as concentric rings of varying intensity about the incident beam. In 1937, GP Thomson received the Nobel Prize for this work, jointly with CJ Davison (1881-1958) who also observed electron diffraction using nickel crystals.