Approaching the Geographic South Pole (or North Pole) the meridians of longitude converge, eventually making a measure of longitude meaningless, as a degree of longitude will become smaller and smaller. At the pole itself, assuming one has accurate enough instruments, all meridians meet. Amundsen reasoned that the extra effort in obtaining longitude could be saved, and he focused on latitude. Amundsen had adopted this strategy after attending a lecture at The Royal Geographical Society in London in November 1909, given by the British astronomer and geographer, Arthur Robert Hinks. In his lecture on Surveying and Cartography at Cambridge University, Hinks put forward this theory when discussing the subject of determining positions near the Pole.