[Footnote 242: The greatest number of mammoth tusks is obtained from the stretches of land and the islands between the Chatanga and Chaum Bay. Here the walrus is wanting. The inhabitants of North Siberia therefore praise the wisdom of the Creator, who lets the walrus live in the regions where the mammoth is wanting, and has scattered mammoth ivory in the earthy layers of the coasts where the walrus does not occur (A. Erman, _Reise um die Erde_, Berlin, 1833--48, D.1, B.2, p. 264). ] [Footnote 243: Among the bears' skulls brought home from this place Lieut. Nordquist found after his return home the skull of a sea-lion (_Otaria Stelleri_). It is, however, uncertain whether the animal was captured in the region, or whether the cranium was brought hither from Kamchatka. ] [Footnote 244: Wrangel's _Reise_, Th. 2, Berlin, 1839, p. 220. ] [Footnote 245: According to a paper in _Deutsche Geografische Blaetter_, B. IV. p. 54, Captain E. Dallmann, in 1866, as commander of the Havai schooner _W.C. Talbot_, not only saw but landed on Wrangel Land. As Captain Dallmann of recent years has been in pretty close contact with a large number of geographers, and communications from him have been previously inserted in geographical journals, it appears strange that he has now for the first time made public this important voyage. At all events, Dallmann's statement that the musk-ox occurs on the coast of the Polar Sea and on Wrangel Land is erroneous. He has here confused the musk-ox with the reindeer. ] [Footnote 246: Cf. _Redogoerelse foer den svenska polarexpeditionen ar 1872-73_ (Bihang till Vet Ak. handl. Bd. 2, No. 18, p. 91). ] [Footnote 247: A more dangerous kind of icing down threatens the navigator in severe weather not only in the Polar Seas but also in the Baltic and the North Sea. For it happens at that season that the sea-water at the surface is over-cooled, that is, cooled below the freezing-point without being frozen. Every wave which strikes the vessel is then converted by the concussion into ice-sludge, which increases and freezes together to hard ice so speedily that all attempts to remove it from the deck are in vain. In a few hours the vessel may be changed into an unmanageable floating block of ice which the sailors, exhausted by hard labour, must in despair abandon to its fate. Such an icing down, though with a fortunate issue, befell the steamer _Sofia_ in the month of October off Bear Island, during the Swedish Polar Expedition of 1868. ]