6. For a long time the “ice-holes,” seen by Wrangel and Morton, were regarded as indications of an ice-free Polar Sea. With regard to those seen by Morton in 81° 22′, Richardson very justly remarks: “The open water of the Kennedy Channel is not of greater extent in the month of June than the open spaces which have occasionally been seen in summer on the north of Spitzbergen by whale-fishers.” Wrangel, when he describes the “Polynjii,” which he saw on the east of the New Siberian Islands, accounts for them by the action of a local coast-wind; and yet Wrangel would have been the first to favour the notion of an inner Polar Sea, for he still thought, in opposition to Scoresby, that ice could not be formed on the open sea, because of the absence of land as a support for the ice in its formation. 7. The first practical application of the theory of an open Polar Sea was long ago devised by Plancius; the discovery, namely, of a route in high latitudes to China. But the expeditions to the North Pole, properly so termed, sprang also from this theory, which was held with the greatest pertinacity. The evidence of unsuccessful undertakings was always met and outweighed by the counter-experience of one favourable year in the ice. Thus Barentz, in the exceedingly propitious summer of 1594, advanced without difficulty one degree of latitude beyond the northern extremity of Novaya Zemlya, while his successors frequently encountered insurmountable difficulties at Cape Nassau, and he himself in the following year, 1595, found the state of the ice changed much for the worse. In the years 1871, 1874, Mack, Carlsen, and the two Austro-Hungarian expeditions came upon an open sea in the very places where very few, if any, water-ways were to be seen in 1872 and 1873. In the summers of 1816, 1817, the mighty stream of ice on the coast of East Greenland had decreased to such an extent that Scoresby met with little ice between 74° and 80° N.L., but since then whalers have constantly seen the heaviest ice there, heavier than anywhere else. In 1753 and 1754, the Sea of Kara and the Novaya Zemlya Sea were free from ice. But in subsequent years the whale-fishers knocked in vain at their ice-barred entrances. In 1823 Lütke from a point on the west coast of the Sea of Kara saw that sea without ice; but, in the middle of August, 1833, Pachtussow found the western side of that sea open, while in the previous year he himself could not pass the Karian Gates. Again in 1743 and 1773, the North Spitzbergen Sea held out promises the most inviting, which might possibly have permitted the reaching of a still higher degree of latitude than that which Nordenskjöld and Koldewey attained in 1868. Sir John Ross, in the first year of his second voyage, found all things most favourable for navigation; but in the following year the very reverse; and Sir James C. Ross experienced the same alternation of circumstances in the Southern Polar Sea. In 1850, Penny found the Wellington Channel