In the summer of 1802 he started down the Danube with a companion Jacobsen, who broke down at Smyrna a year later. His journey was by Constantinople, where he stayed six months, thence through Asia Minor to Smyrna, then again through the heart of Asia Minor to Aleppo, where he remained from November 1803 to April 1805, and made himself sufficiently at home with Arabic speech and ways to travel as a native. Now began the part of his travels of which a full journal has been published (April 1808 to March 1809), a series of most instructive journeys in Jordan and Palestine and the wilderness of Sinai, and so on to Cairo and the Fayum.