A Swedish naturalist, born in Helsingfors; after several successive voyages and explorations in the Arctic Sea, in which he paid frequent visits to Spitzbergen, where he measured an arc of the meridian, in 1878-79 discovered the North-East Passage by traversing, along the N. shores of Europe and Asia, the whole Arctic Sea from the Atlantic to the Pacific; has written accounts of his expeditions; b . 1832.