The plate archive of Hamburg Observatory comprises 45,000 photoplates approximately dating from December, 1911 until the end of the 20th century. In a unique project, the photoplates have been digitized since 2010.
The archive comprises 114000 scans approximately (i.e. buildings 1909-1912, expeditions, annual reports).
The collection documents the creative work of this remarkable designer, optician, and inventor at Hamburg Observatory and elsewhere (around 10,000 documents, notes, drawings, and photographs)