We know already how they learned that rivers open their own gateways through the mountains; how they know rocks are made over in the fairyland of change; how they know the ancient glaciers scattered the boulders over mountainside, valley, and field; how they know the mountains are children of the sea.
All this and more we have been reading in the written language of the rocks, but there are other things in this rock script that I have kept for this last but one of our pleasant talks, so that they might serve as a kind of summary and remembrance of all that has gone before.
A WALL THAT VULCAN BUILT
I've said it several times before, but I can't help saying it here again, how much more wonderful the ways of Nature are than was ever dreamed of even in the wonder tales of the Greeks! Take this great iron wall, for example—a wall of the iron rock called "lava"—and who would suppose that it was made by natural forces? It was driven in a molten state into a crack in overlying rock. After it cooled, the rock above and on either side of it, being of softer material, was worn away. This wall is near Spanish Peaks, Colorado. It is 100 feet high and some 30 feet wide. Colorado boys, on their vacations in that region, run along the top of it for miles.
I. The Mysteries in Marble Walls
Take a piece of marble for example, such as you see along the walls of our great modern buildings. There's a story for you! Why, if half the things it tells had just happened, or even just been discovered by some enterprising reporter, we should see pages and pages about it all in every newspaper in the land.
HOW MARBLE RETELLS THE WORLD HISTORY
In that piece of marble alone you have a pretty full review of the earth's history; of many of the most important things we have seen and heard about since we all started out together in [Chagter I]. It tells of strange life in ancient seas; of being buried deep in the earth under immense pressure, and where it could feel the intense heat of the rock at the centre, and of coming up again completely changed; transformed from the substance of a dead sea creature's shell to a crystallized stone beautifully colored and of many patterns; of the chemistry of the world underground and the laboratories in which its lovely coloring were made and blended; and solid rock threaded through rock with a skill that no worker in mosaic has ever equalled; drawn out and fixed in mere films of white, fading into the rich dark of the marble around them like white clouds shredded by the winds.
