From the Hans Christian Andersen biography "The Life of Hans Christian Andersen. Day By Day", written by DPhil Johan de Mylius:
1858
To Germany and Switzerland10 April
Reads "Dynd-Kongens Datter" (The Marsh King's Daughter) aloud for Fr. Paludan-Müller.
30th April - 1st May
At Frederiksborg Castle, first to dine, then reads aloud in the evening. Has a long conversation on the next day with Countess Danner ("who was very gracious and extremely charming", the diary).
15 May
Release of Nye Eventyr og Historier. Anden Samling (New Tales and Stories. Second Installment), including "Dynd-Kongens Datter" (The Marsh King's Daughter), "Hurtigløberne" (The Racers) and "Klokkedybet" (The Bell Deep).
1858: To Germany and Switzerland
16 May
Travels to Sorø. Continues to Basnæs Estate on 18th. Presumably back in Copenhagen approx. 28th May.
15 June
Travels to Sorø. Continues from there with Harald Drewsen (the younger brother of Viggo and Einar, son of Adolph Drewsen and Ingeborg Collin) aboard the steamship 'Diana' from Korsør to Flensburg. On through Altona/Hamburg, Hannover, Kassel, Guntershausen, Frankfurt, Heidelberg, Freiburg, Basel, Luzern to Brunnen (arriving 27th June, going on outings from here to Andermatt and Hospenthal). Continues on 3rd July via Lachen, Glarus, across Lake Wallenstädter to Ragaz. After a mountain climbing trip on 6th July they continue to Zürich, Schaffhausen, Konstanz, Lindau, Augsburg and Munich (arriving 11th July). On the 16th, on to Nuremberg, Bamberg, Plauen and Leipzig (where he meets with the publishers Wiedemann and Lorck). Arrives in Dresden on 20th.