Portrait of German historian and geograph <a href="https://en.wikipedia.org/wiki/Konrad_Mannert" class="extiw" title="en:Konrad Mannert">Konrad Mannert</a>.
draft of Lutz Lacroix, painted on stone by Schimon Lacroix (both first half of the 19th century)
first half of the 19th century
taken from: Dieter Kuhn: <i>Mannert: ich danke dir. Über eine Quelle zu Arno Schmidts „Kosmas“</i>. In: <a href="https://de.wikipedia.org/wiki/Bargfelder_Bote" class="extiw" title="de:Bargfelder Bote">Bargfelder Bote</a>, Lieferung 134–136, März 1989, p. 4–33, here p. 9 (they got it from the Universitätsbibliothek Erlangen)