EXPLORATION OF ANTARCTIC LANDS. 487 
were all iceworn and very flat, in some places scored with cracks, though 
to a much less extent than at the place of our previous landing. There 
were numerous veins of quartz, some quartz in the form of amethyst, 
and a quantity of copper ore. There were no erratics. All the islets 
of the neighhourhood had the same appearance, like great whale-backs 
appearing above the sea. The polished surface extended to just below 
the surface of the water, and there were also, near the islet where we 
landed, several glaciated rocks scarcely emergent. 
The whole group seems to form a plateau which has been profoundly 
glaciated, and of which only the higher portions now appear, but this 
plateau has nothing in common with the continental shelf, the whole 
of the district which we have explored presenting very clear evidence 
of a submerged region. From another point of view, these islands are 
by no means the stumps of mountains worn down by marine erosion ; 
they afford evidence of a great extension of glaciers in some by-gone 
period. The whole channel, which we were now about to leave, had 
doubtless at one time been filled by a great glacier which flowed to the 
Pacific. The cutting off of the summits of these islands may be its 
work, 
At 3 p.m. we turned the southern point of the sierra and steered 
north-eastward in order to continue our exploration of the main channel, 
which is divided by low islands into several branches. It is a question 
of some interest whether it is the Bismarck strait of Dallmann. The 
sierra reappeared suddenly in the south, on the other side of the 
entrance to the channel, and continued in a straight line to the south- 
south-west, but a lower parallel ridge appeared west of the main chain, 
and beyond it a range of islands, the summits of which were still 
lower, bordered the coast, the whole evidently forming a tectonic chain. 
Towards the interior a gentle slope of glacier connects the sierra with 
a higher mass buried under the inland ice. At 4 p.m. we made the 
seventeenth landing on an islet not far from the east coast of the island 
we had come round (XVII on map, Fig. 2). Racovitza, Cook, Danco 
and I were left ashore for some hours while the ship continued her 
route. The end of the island where we landed was a great rookery of 
penguins and cormorants, and the snow was much soiled for a consider- 
able distance from the shore. The rocks, which are much glaciated, were 
fairly level, and at the heads of the little bays, out of reach of the waves, 
we found numerous pebbles and small erratic blocks of gneiss, various 
granites, and porphyry, but neither pudding-stones nor basalt ; and, as 
I saw no erratics elsewhere, it is probable that these were carried by 
floating ice. A rocky hill was uncovered to a height of 70 to 100 feet, 
and above that was the layer of ice, which, in places of more gentle 
slope, descended to the shore. There was little névé on the surface, and 
all of it melting ; water trickled away on every side, though not in any 
great quantity. The surface of the ice was traversed by vertical cracks, 
