There is a note in "Notebooks and Journals" that Twain had written two
chapters on Hamburg but decided to leave them out of his manuscript.
 If these are actually available, I'd certainly like to see them.  Here
is a link to what I have on Hamburg:  https://twainsgeography.com/conte
nt/hamburg  This page has a link to a transcription I did on the
Hamburg section of Bædeker's tour guide.  Mark Twain existed on the
cusp of Industrialization and it is startling to consider just how
different places like Hamburg were from today.
-- 
 There are more things in heaven and earth, Horatio, than are dreamt of
                          in your philosophy.
                        http://bscottholmes.com