During a tour in 1834-1835 Waltershausen carried out a series of magnetic observations in various parts of Europe. He then gave his attention to an exhaustive investigation of the volcano of Mount Etna, in Sicily, and carried on the work with some interruptions until 1843 including with Christian Heinrich Friedrich Peters. The chief result of this undertaking was his great Atlas des Ätna (1858-1861), in which he distinguished the lava streams formed during the later centuries.