The apex of the triangle unites the Sea of Greenland with the polar basin.

This region comprised between Greenland and Spitzbergen constitutes the outlet of the ice from the polar basin, and at the same time affords a passage toward the north of the farthermost branch of the Gulf Stream. This Atlantic current, which warms the western coast of Spitzbergen, passes around the northwest angle of this archipelago and loses itself in the Arctic basin, as Nansen has demonstrated. The oceanographic régime of the basin depends then, first of all, on the topographic conditions existing in the northern part of the Sea of Greenland. This region is in general blocked by ice,

and its depth is unknown to us except in the immediate vicinity of Spitzbergen.

Nansen believes that this gate of communication is constricted by a submerged ridge extending between Greenland and Spitzbergen, and rising to within 800 meters of the surface.

The origin of this hypothesis is curious; first of all, it has a hydrographic foundation. Nansen has shown that in the polar basin proper, the deeper lying water has a density of 1.02825, while the samples collected by Amundsen in the Sea of Greenland yielded, for the water from the depths of the basin, values a little less (about 1.02811). Nansen concludes from this that if the waters have not the