Ebert Spectrometer Reflections

The Ebert spectrometer, named for its inventor, the 19th-century German spectroscopist Hermann Ebert, emerged from obscurity after the Second World War to play a significant role in the exploration of the solar system. I had a part in its resurrection, and the Ebert spectrometer has played a dominant role in my scientific career. Therefore I've taken the trouble to look into its history. The evolution of this instrument, now a century old, was curiously haphazard and fraught with mistakes. I have attempted here to put these events into chronological, and somewhat autobiographical, perspective.