Archive of Hagen-Bessel-Neumann-Koenigsberg

                  http://www.gelehrtenfamilie-koenigsberg.de/ArchivStiftung/Archiv_der_Stiftung.html

Former in Bückeburg, since 2007 in Berlin, exists an archive of the Königsberg-scientists K.G.Hagen, F.W.Bessel, F. Neumann and their descendants (mentioned in liturature e.g. as HBN-Archive Bückeburg). It manages the books and exhibits for two foundations:
1.)  Franz-Neumann-grant-foundation. It was founded by the father of E. Neumann, the physicist Franz Neumann for his 50th doctor anniversary (1876). The bases for the foundation was given by emperor Wilhelm I.  (Lit. Geh. Staatsarchiv Dahlem, Archivstr. 14, I. HA, Rep. Va Rep. Va Sekt 11, Titel XI, Nr. 50, Bd. 1) The former foundation was integrated in 2003 as “Zustiftung” into the “Stiftung Königsberg” under the abbreviated name "Franz-Neumann-Foundation"

2.)  The"Karl-Gottfried-Hagen-Stiftung" was  founded in 1871 by Ernst August Hagen  for the care of the widowed or single female descendants of the popular chemist Karl Gottfried Hagen. Lit: Hagen, Heinrich.: August Hagen. A memory document for its one hundredth birthday. Mediator, p. Berlin 1897.)

The archive of both foundations contains a part of the estate of all teachers, scholars and artists, mentioned in the homepage see above.  The main part of the estate became the national library of 37037 Göttingen, hand-manuscript-department Papendiek 14. (Estate Ernst Christian Neumann Acc. Mss. 1994.6.1, -- 1994.34, -- 1995.9 ) http://www.sub.uni-goettingen.de

 For example: In Göttingen (and a copy in Franz Neumann-Stiftung, Berlin) you will find a manuel script (written down by the cholar E. Neumann in Berlin 1856/57) of the lecture of H. von Helmholtz (Göttingen Cod.Ms.E.C.Neumann 2a,5) and A. von Graefe (Göttingen Cod.Ms.E.C.Neumann 2b,3) as well of R. Virchow (Göttingen.... 2b,5) F. Arlt L.Traube, A. HaynK. Sudhoff and others

Ad 1.) In this HBN-family-archiv in Berlin exists all offprints of the publications of Ernst Neumann as well as exhibits like bronze badges (Stanislaus Cauer - see button Award) and e.g. the Ruete-Graefe- ophthalmoscope (shown here), concerning to Ernst Neumann as pupil of A. von Graefe and H. von Helmholtz.

Ernst Neumann was a pupil of H. von Helmholtz, who discovered the ophthalmoscope 1850 in Königsberg, and from  A. von Graefe, Berlin, who is also well known as founder of the german ophthalmology. http://www.berliner-medizinische-gesellschaft.org -continue “Extras” and “A. von Graefe” or “Kunst im Medizinerviertel”

This Ruete-Graefe ophthalmoscope from the second half of the 19th century was in the estate of Ernst Neumann, produced by Paetz and Flohr, precision engineer Berlin. Look at  www.Franz-Neumann-Stiftung.net