"Did you notice this?" said one. "The material is not separated into layers and divided up into coarse, finer, finest as the sediment of pebbles, sand, and mud is separated and divided when it settles along shores. These pebbles, this sand and clay, are all mixed up."
"Look at this, will you?" (Here imagine a Learned Somebody picking up a pebble with a scratched face like mine.) "Water never scratched anything like that. Here are a lot more of these pebbles, all with their faces scratched."
"And just see how all these scratched pebbles have flat faces," cried another of these famous grown-up boys in these great field excursions. "It looks to me as if they had been ground against something hard—another rock, say; and for a long time."
HOW THE QUESTION WAS FINALLY SETTLED
Well, to make a long story short, they found that the glaciers of the Ice Age, those great bodies of flowing ice, were the only things that could have brought all this material together from such widely separated regions (as shown by the different kinds of pebbles), and left them all mixed up as they were; and the faces of many pebbles scratched and flattened where they had been ground along.
And then, to put the question entirely beyond dispute, they find that the glaciers are carrying down pebbles and stuff in just this way to-day, and piling it up in hills in the valleys at the foot of the mountains. Only the hills of to-day are much smaller, because the glaciers themselves are so small compared with the giants of the past.
HOW THE OLD MEN MOVED THE HILL FURNITURE ABOUT
This picture of a glacier in Alaska shows you just how the Old Men of the Mountain moved the hills about, that time. As indicated by the white lines—which, of course, were added to the picture for the purpose—the Alaska glacier melted back, leaving just such heaps of pebbles, boulders, and soil as made certain types of hills. Then from 1910 to 1913 it advanced again, thus picking up the very hills it had laid down and setting them farther along, just as the glaciers did in the Ice Age.
HOW THE HILL FURNITURE WAS MOVED ABOUT