The First Thule Expedition (1912, Rasmussen and Freuchen) aimed to test Robert Peary's claim that a channel divided Peary Land from Greenland. They proved this was not the case in a journey across the inland ice that almost killed them. Clements Markham, president of the Royal Geographical Society, called the journey the "finest ever performed by dogs." Freuchen wrote personal accounts of this journey (and others) in "Vagrant Viking" (1953) and "I Sailed with Rasmussen" (1958). He states in "Vagrant Viking" that only one other dogsled trip across Greenland was ever successful. When he got stuck under an avalanche, he claims to have used his own feces to fashion a dagger with which he freed himself.