“The reason is simply this, boys,” said the skipper. “That kind of stuff has all been hurled back to the edge of the pack on the main barrier of ice by the force of the northerly wind.
“This land-ice is quite different,” he continued, “from any you have ever encountered in the North Pole regions. Our earlier navigators in their tubs of ships sighted it, and some of them sailed along its edge for hundreds of miles; and as they could find no inlet before they were driven off by storms, they jumped to the conclusion that this great barrier, this solid, cliff-like wall of blue or green or striated ice, hundreds of feet in height at some places, went all around the Antarctic, warning them that thus far might they come but no farther.”
“But what, then,” said Charlie, “do you mean by land-ice? I’m all in a fog.”
“Well, lad, you must first imagine a time in the remote ages when this great unknown Antarctic continent was a land of mountain, forest, and flood, with rivers finding their way down very extensive valleys to pour their bright waters into the sea. Imagine, too, if you please, that these beautiful valleys were in ages far remote from ours clad in verdure, in jungle, heath, and forest, and that a fauna distinct from ours existed here, that immense mammoths and mastodons dwelt here, and mayhap flying alligators, though probably no other creature at all bearing any resemblance to the form of human beings.
“Then let this age pass out of your mind, and another and colder period slowly commence—a glacial period, for instance, during which the rivers and lakes were frozen, and there was no more rainfall, because the mists or dews driven over yonder continent were then condensed, and fell as snow. The long storms of winter would soften and the snows melt somewhat during the Antarctic summer, to form ice again when the dark, wild weather returned. So the valleys would be partially filled up with great glaciers. These must move down towards the sea, though extremely slowly—broad Mississippis of ice and snow. When this so-called land-ice reached the water, it would form a barrier, and monster bergs would get detached and float away, leaving the striated cliffs with their wave-washed caves at the edge. In the gigantic, snow-covered, square blocks that float away on the currents of ocean, these caves form archways, so that you can sometimes see right through the bergs, or even sail a boat through them.
“Well, that is land-ice, but the sea-ice is formed of something like the same pancake and hummocky ice we find in the far, far north, and the peculiarity of the Antarctic seas of ice is this—the land-bergs, if I may so call them, often get embedded or entangled in pack-ice, high above which their great bulk heaves, as towers a ship of battle above a tugboat or dinghy. In course of time the land-bergs are hollowed and tunnelled by the waves on which they float, till they break-up, or divide, forming the strangest-shaped pieces imaginable.
“Another thing which proves that a long way into the interior of this South-polar region land extends is this—débris of earth and blocks of rock are brought down on the glacier that, as an examination of the sea’s bottom proves, could have descended in no other fashion.”
“It is all very wonderful!” said Charlie.
“I wonder,” said Walter, “if any mermaids dwell in these caves of ice?”
Captain Mayne Brace smiled and answered.