The papers include diaries, research notes, correspondence and drafts of published work relating to Eiby's scientific work on earthquakes, geophysics, and astronomy as well as to his numerous other interests including theatre, music and film. Included are several unpublished plays and novels. Most material dates from the period after 1950, however there are some earlier papers, including family papers going back to 1856. Also includes correspondence regarding the preservation and history of Dominion Observatory and papers relating to the Royal Astronomical Society of New Zealand.