Of course you understood all along that these aren't the very same butterflies that came with the glaciers, yet in shady glens in high mountains, where the snow never melts, people do sometimes find masses of ice, which, there is every reason to believe, have been there since the Ice Age. And sometimes thick veins of ice, buried hundreds of feet under pebbles, boulders and soil, are struck in sinking wells. These are known as ice wells; huge ice water tanks that never need filling!
II. A Little Visit with the Glaciers
But if the ice masses in the shady glens and under the old moraines may be said to be pieces of the Ice Age left over, the glaciers of to-day are, in a sense, the Ice Age itself. For these glaciers do, on a smaller scale, what Mr. Labrador and his partners in northern America, Europe, and Asia did on a large scale so many centuries ago. Suppose now, like Agassiz, we trace a glacier to its source. It will be a long journey, all steep, some of it almost straight up, and along chasms of slippery ice with sudden storms that hide the chasms and blind your eyes and take away your breath. The first part of our journey is over a field of ice, gray with the dirt of weathered rock from the mountain sides. Along its borders are those sharp-edged stones neatly packed in rows, that our geography tells us are called "lateral moraines." It has another row of these stones sticking up right in the middle of its back, like the sharp-pointed vertebræ of the ceratosaurus.
By noon, as often happens in the Alps as elsewhere at this time of year, a rain comes up and we lunch under the shelter of a tumbled heap of rocks. Watching the downpour drift across the desolate wastes we think what jolly times like this Agassiz and his companions had in their little hall of science under the big stone. After lunch we start again, and although it's stiff going, and it takes a lot of this thin air to make one good breath, we spare a little, now and then, for shouting, to hear the wonderful play of the echoes among the mountains. We go through all kinds of weather—rain, mist, snow. Then suddenly we burst into blinding light. The sun is so dazzling on the snow, now no longer covered with dirt and mountain débris, that we must all put on our colored glasses. In some places, among bare rocks that absorb the sun's heat, it is positively sultry.
The fields around us look like an ocean turned to stone. Waves are formed in the surface ice of the glacier because surface ice moves faster than the main mass beneath. On the bordering mountain walls the ice rises into still greater waves "foaming about the feet of the dark central crests like the surf of enormous breakers." And this great, still image of the parent sea, from which the air currents carried the moisture that made it, has eddies and whirlpools, and like the troubled sea, "whose waters cast up mire and dirt," the glacier, where it swirls along its shores, works pebbles and dirt to the surface. Often this material is carried into the centre of a whirl, as sea weeds and the rubbish of the seashore are driven into eddies among the rocks.
Somebody must have been here just ahead of us. Isn't that a dark glove over there? We come closer. What at a distance seems to be a glove proves to be a hole in the ice so deep it looks dark. Lying flat and carefully peering over the edge we look into something strangely beautiful—an ice palace, with icicles in fantastic groups hanging from the roof. Through this roof the sun comes in delicate floods of pale green light, the combination of the yellow rays with the blue of the ice. We drop pebbles into the hole. They rattle down and down with long, dull echoes, dying away. We can hear the murmur of running water. Gusts of cold air come up that bite like the wind on a sharp winter day.
These underground palaces of art start as great cracks in the ice, called "crevasses," from a French word meaning a crevice. They can usually be seen plainly as yawning chasms, but sometimes are so bridged over by the snows that a small, dark hole is all you see. And we might not see that in time. This would be very bad, for these snow bridges are often quite thin. One might like to go down in a crevasse and explore about in this beautiful dream world—but not when one wasn't looking!
Even when one is looking and is as careful as can be it's dangerous. But still you may be sure that the famous men who have studied glaciers have done it, for every true man of science likes to get at the bottom of things. It was Agassiz who first went down in this way into the heart of a glacier. It was while he was making his studies in the Alps, and he came very near being drowned in one of the streams that always flow at the bottom of a crevasse, for these crevasses, breaking up the ice, increase the rate of melting. (You know broken ice will not keep so well as a big block.)
WHAT TWO BOYS SAW IN THE FAIRYLAND OF ICE