294 ANTARCTIC EXPLORATION. 



;iud hove his lead GOO fathoms deep where Wilkes had drawn a moun- 

 tain. He tells us that the weather was so very clear that had high 

 land been within 70 miles of that position he must have seen it ("Eoss's 

 Voyage," 1278), More recently Nares, in the Challenger, tested another 

 l)art of Wilkes's coast line, and with a like result; and these circum- 

 stances throw doubts upon the value of his reported discoveries. 

 D'Urville subsequently followed a bold shore for a distance of about 

 300 miles from 130° E. to 142° E. longitude; whilst in 67° S. latitude, 

 and between 45° E. and G0° E. longitude, are Euderby's and Kemp's 

 laud.3. Again, there is land to the south of the Horn which trends 

 from 45° to 75° S. latitude. These few discontinuous coast lines com- 

 prise all our scanty knowledge of the Antarctic laud. It will be seen 

 from these facts that the principal geographical problem awaiting solu- 

 tion in these regions is the interconnection of these scattered shores. 

 The question is, do they constitute parts of a continent, or are they, 

 like the coasts of Greenland, portions of an archipelago, smothered under 

 an overload of frozen snow, which conceals their iusularity ? Koss 

 inclined to the latter view, and he believed that a wide channel leading 

 towards the Pole existed between North Cape and the Balleny Islands 

 ("Eoss's Voyage," 1221). This view was also held by the late Sir 

 Wy ville Thomson. A series of careful observations upon the local cur- 

 rents might throw some light upon these questions. Eoss notes several 

 such in his log. Off Possession Island a current, running southward, 

 took the ships to windward {ihUL, 1195). Off Ooulman Island another 

 drifted them in the same direction at the rate of 18 miles a day {ibid., 

 1204). A three-quarter knot northerly current was felt off" the barrier, 

 and may have issued from beneath some part of it. Such isolated 

 observations are of little value, but they were multiplied, and were the 

 currents correlated with the winds experienced the information thus 

 obtained miglit enable us to detect the existence of straits, even where 

 the channels themselves are masked by ice barriers. 



Finally, it is calculated that the center of the polar ice-cap must be 3 

 miles, and may be 12 miles deep, and that the material of this ice 

 mountain being viscous, its base must spread out under the crushing- 

 pressure of the weight of its center. The extrusive movement thus 

 set up is supposed to thrust the ice cliff's off the land at the rate of a 

 quarter of a mile per annum. These are some of the geographical 

 questions which await settlement. 



In the geology of this region we have another subject replete with 

 intei'est. The lofty volcanoes of Victoria Land must present i)eculiar 

 features. Nowhere else do fire and frost divide the sway so com- 

 pletely. Eoss saw Erebus belching out lava and asheS over the snow 

 and ice which coated its flanks. This circumstance leads us to specu- 

 late on the strata that would result from the alternate fall of snow and 

 ashes during long periods and under a low temperature. Volcanoes 

 are built up, as contradistinguished from other mountains, which result 



