Encouraged by naturalists Robert Jameson and Joseph Banks, whaler William Scoresby became an expert on the natural and physical processes at work in the European Arctic. Original letters between Scoresby and these naturalists, housed in the archive of the Whitby Literary and Philosophical Society (Yorkshire, England), document in the language of the times his biological observations and experiments in physical oceanography. Scoresby's researches resulted in An Account of the Arctic Regions, with a History and Description of the Northern Whale-fishery in 1820, which became a seminal work in Arctic science. Among the prescient observations in An Account of the Arctic Regions was a description of deep strata of water, under currents moving in different directions from the surface. A copy of An Account of the Arctic Regions was given as a gift to Norwegian scientist-explorer Fridtjof Nansen in 1897 upon the completion of the Fram expedition (1893–1896) and still resides in his personal library in Norway. In it is an underlined passage, suggesting that Nansen had read the whaler's book, perhaps in preparation for writing his own volumes on Arctic science, The Norwegian North Polar Expedition, 1893–1896 (1900–1906). Then, by inference, Nansen had been familiar with Scoresby's description of the under currents. In The Norwegian North Polar Expedition Nansen wrote that he had observed similar patterns of deep-water movements during the Fram expedition. This phenomenon must have perplexed him, because he posed the problem to the Swedish mathematician-oceanographer Vagn Walfrid Ekman, who mathematically described the water movement. Ekman's resulting model, a spiral staircase of descending deep-water currents, became known as the Ekman Spiral.