Twain and Joseph Twichell joined Twain's family in Lucerne August 12, 1878. They stayed at the Schweitzerhof Hotel until August 21. Twain returned to Lucerne in August of 1897. (See Baden to Lucerne)
From Page 260-1 The Life of Mark Twain - The Middle Years 1871-1891:
August 10 Saturday – In the morning the men explored Dilsburg Castle [Rodney 103]. Sam and Joe started back to Baden Baden by train. They took a swift raft ride of the lower river to Heidelberg, plowing the raft into a bridge [103]. “Blazing hot in train.” They stopped at Friedrich [note: I can find no reference to what or where is Friedrich] . From Sam’s notebook:
Friday, August 9, 1878 – Twichell and Sam took a boat from Heilbronn for a trip down the Neckar River, stopping for beer and chicken at Jagtfeldt, then continuing toward Hirschhorn in a new and smaller boat [MTNJ 2: 132].
Sam’s notebook:
“Hasshersheim (?) town where we tarried & took beer & H [Twichell] went swimming above where 25 girls were & was warned away. Below this town on right bank, 200 ft up on top of the steep bank, castle of Hornberg, high old vine clad walls enclosing trees, & one peaked tall tower 75 ft high” [2: 132-3].
Thursday, August 8, 1878 – Joe and Sam took the train (See the Elsenz Valley Railway) up the river valley to Wimpfen. Mark Twain describes the visit to Heilbronn in A Tramp Abroad:
Tuesday, August 6, 1878 – Clemens and Twichell walked from Allerheiligen to Oppenau, Germany, ten miles [MTNJ 2: 47, 129]. They then took a train from Oppenau to Heidelberg “through clouds of dust” [129].
July 25 Thursday – The second day of the carriage trip over country that Sam and Joe would tramp in early August. Eclectic entries from Sam’s notebook:
Monday, August 5,1878 – Sam and Joe left by Baden-Baden rail to Achern, for a week-long tramp. He describes this first day in a letter to Livy:
Sunday, August 4, 1878: Sam and Joe took another one-day excursion from Baden Baden to Ebersteinburg to Nuehaus to Gernsbach, where they drank beer. The pair returned to Baden Baden in the evening. (DBD)
Friday, August 2, 1878: Sam and Joe took a short excursion (6 miles) to the popular Altes Schloss (Favorita Schloss), a conspicuous ruin on the summit of a hill outside town. Sam’s notebook holds an entry paraphrasing a guide book, that:
“...no tourist should fail to climb the mountain & enjoy the view. Hired boy to climb the Mt & examine (or enjoy?) the view. He felt well repaid for all his trouble.”
Later in the day they walked back through the woods to Baden Baden.
(DbyD)
See A Carriage Ride Through the Back Forest
July 24, 1878: The Clemens party started out on a three-day carriage trip through the Black Forest. They stayed at inns along the route.
The party more than likely took what Bædeker describes as the direct route to Forbach: