Routes and dates of the Willem Barents and Isbjorn voyages are shown. Areas of sea ice are shown. Depth shown by soundings. Approximate line of 100 fathoms depth is shown. From: Proceedings of the Royal Geographical Society and monthly record of geography. Vol. 2 (1880), no. 1, pp. 1-40; held in Firestone Library. Call number: G7 .J6873