rounded by land, which does not appear to be anywhere much deeper than 2,000 fathoms, the three deepest soundings taken by Nansen and Sverdrup being 2,195 fathoms, 2,102 fathoms, and 2,020 fathoms. Unfortunately, in the three soundings these explorers took between 15° E. and 70° E., including the farthest north one, they did not succeed in reaching the bottom, these three soundings being "1,638 fathoms no bottom." Within five geographical miles of the Pole Admiral Peary obtained a sounding of "1,500 fathoms no bottom." Where the North Polar Basin is not bounded by land, as at the Behring Straits and between Spitsbergen and Greenland, it is bounded by ridges of considerably less than 2,000 fathoms in depth. The researches of the Duke of Orleans and the Mylius Erichsen Danish Expedition tend to show that a ridge covered by quite a small depth of water exists between Spitsbergen and Greenland.
A proper conception of the bathymetry of Polar seas is necessary for an adequate discussion of physical problems connected with the temperature, salinity, specific gravity and circulation, and the effect of wind, air-temperature and other phenomena that affect these seas. The physical problems of ice-covered seas are much more complicated than in seas where there is no ice, because, as we have seen
