Page:Popular Science Monthly Volume 50.djvu/344

328 position (in a north-and-south displacement) by hundreds of miles. Thus, in approximately the meridian in which, in 1823, Weddell reached the surprisingly high latitude of 74° 15′ south, the famous navigator Cook, nearly half a century earlier, was stopped in latitude 60°; and in 1855 Captain Grant found himself confronted by the impenetrable flat-topped barrier, three hundred to five hundred (?) feet in height, in latitude 56° 50′—40′ west longitude. Both of the arguments here stated have their force, but in how far they prove their case future exploration or penetration alone can show. Ice movements similar to those of the south take place in the arctic regions, and they are largely determined by the winds and currents which sweep over or govern a virtually open sea; but it should be noted that the ice pack of the north is very different from what is commonly designated the "barrier" of the south, with its stupendous wall precipices of one hundred and fifty to three hundred (or five hundred?) feet elevation; such fronts in the arctic regions belong exclusively to isolated icebergs or to the terminal faces of ice sheets (glaciers) which debouch into the sea and terminate at no great distance from the mainland. The bounding ice walls of the northern face of Melville Bay are examples of this kind. The main pack, or that which blocks navigation in the north, is a surface, regular or irregular, which rises but little above the level of the sea, except where it is tossed up into shingles and hummocks, or into those irregular eminences which have been by some identified with the so-called "palæocrystic" ice. On the other hand, a counterpart of the southern barriers is to be found in the land terminations of some of the giant glaciers of the interior, whose "Chinese walls" have been so graphically described in the explorations of Grinnell and Grant Lands (Greely).

It is unfortunate that the term "Antarctic Barrier" should ever have come into use, as it has been made to cover a variety of structures, and has led to confusion in the interpretation of the special features which it designates. There is no question, as Murray has pointed out, that much of the so-called "barrier" of Wilkes is merely ordinary pack ice—some of it, indeed, in the brash or broken condition; therefore, considerable allowance must be made in the acceptance of that assumed girdle which is supposed to define a continent. A point that probably favors the (Petermannian) view of partially oceanic conditions within the ice is the presence of strong northwardly trending currents, which have been observed by both earlier and later explorers. Thus, at his farthest southing, in 1894–’95, in latitude 74° 10′, Captain Kristensen, of the Antarctic, met with such currents trending almost due northward opposite Victoria Land, and the question naturally suggests itself, Is this a direct current, or one that is