The Ernst Heinkel-designed seaplane owned by Norwegian aviation pioneer Leif Lier. See other picture for more information. Photo year given as 1927. However, the registration is listed as crashed on 15 August 1924. Photo from: Nasjonalbiblioteket (Norway)

'The German Casper airliner which arrived first in the prize flight to Gothenburg with captain Leif Lier.' An interesting puzzle in the Dutch national archives. According to the German Wikipedia, Caspar S.I D-292 won a competition in Gothenburg in 1923 (during the ILUG exhibition), and D-292 was sold to Leif Lier from Oslo as N-23. The S.I reconnaissance floatplane was designed by Ernst Heinkel and it eventually became the Heinkel HE 1. It was produced in Sweden for the Swedish air force but also for German undercover training outfits. Photo by: Robert Sennecke / Nationaal Archief (Netherlands)