Page:Popular Science Monthly Volume 50.djvu/342

326 with the South Shetland Islands, is also loftily mountainous, ranging to perhaps nine thousand feet, and with volcanic cones as a dominant feature. Lying east of King Oscar II Land, which is seemingly only a portion of Graham Land, are a number of small islands, some of which, as Christensen and Lindenberg, were volcanoes in active eruption at the time of Larsen's visit. This tract of archipelago lying south of the American continent is much less snow-bound than the region about Victoria Land, large areas of bare rock being exposed both on the islands and on the mainland, especially the volcanic slopes. Not improbably the heat of the volcanic cones has much to do with keeping an exposed surface, although it can hardly be supposed that this exposure is entirely due to this cause.

The geographical and geological study of the region under consideration resolves itself into four or more lines of inquiry: 1. Have we a continent in Antarctica? 2. What is the nature of the ice covering? 3. Of what construction are the rock masses? 4. Has Antarctica ever been united with any of the major divisions of the earth's surface which we recognize as continents?

The first inquiry hardly recognizes a positive answer as yet. Wilkes was certain that in the land masses seen by him, or thought to have been seen, we had the positive marks of a vast united continent; Ross, although he had seen more continuous coast line than any other investigator, was exceedingly doubtful on this point, and considered the evidence insufficient for positive determination; Murray, the distinguished geographer of the Challenger Expedition, has gone even beyond Wilkes, and constructed the contours of what appears to him to be true Antarctica, the outlines of which are in the map on the next page. These may be approximately correct or not a matter about as difficult to disprove as to prove but it is certain that the materials upon which this construction is based are hardly sufficient to warrant the mapping. Yet it is almost positive that a vast land area—perhaps two, three, or more of them—underlies the capping of snow or ice; but whether it is entitled to the designation of continent remains to be demonstrated by future exploration. Ross strongly emphasizes the doubt as to whether all the eminences or appearances reported to be land are really such, and he himself admits—cautious observer though he was—to having been deceived on more than one occasion. Murray, again, warns us that much of the ice barrier described by Wilkes is not the true barrier (which is presumed to be the boundary to a not distantly lying terra firma), but merely the cemented pack. It is a significant fact that none of the explorers refer to a distant elevated ice cap, such as everywhere bounds the horizon of the observer looking