The Bad Lands of South Dakota, in which, as in other parts of our great West, so many bones of the ancients have been found, got their name because they are so bad for travelling; that is to say, if you are in anything of a hurry. But if you are just looking around--during your vacation, in June, say--they are anything but bad lands. They are full of interesting secrets. This secret of the ancient bones is only one of them. Another thing they lead us into is the secret history of the hills themselves; and as this particular book is mainly about the face of the earth, the story back of the landscape, as it appears to the traveller, we shall give the rest of this chapter to the origin of the Hill family, using the word "hill" in its broadest sense. If you have looked it up in the dictionary you have found that what people call a "hill" depends a good deal on where they are. The Bad Lands are really hills; but in South Dakota, where these particular bad lands are, they also have what they call the Black Hills, which are really mountains, because they "mounted" to get where they are.[18] They wrinkled up, just as the continents themselves did, when they came out of the sea. Most of the great mountain systems of the world were made in this way, but table-lands may be so cut up by streams in course of time that they look like mountains. [Footnote 18: Mr. Pebble did not mean to say, I am sure, that the word "mountain" comes from "mount," used in the sense of rising. The original of the word mountain comes from the language of the People of the Seven Hills, the Romans, and means a great mass of rock or earth that sticks up.--_Translator._] [Illustration: _Painted by Dewitt Parshall. In the possession of the Metropolitan Museum of Art_ THE CATSKILLS IN A MIST ] The Catskill Mountains are of this type, while real mountains may be so worn down that you would take them for plains. You see, with the Hills and the Mountains, as with other royal families, it isn't the importance of the individual that counts, but the ancestry. Another kind of real mountain, beside the folded-up kind, is the mountain that is made where a rocky plain is split up into great stone blocks by the movements of the earth crust, as it settles around the shrinking centre. In the settling and crushing together of the rock cover around the shrinking ball within, some of the blocks drop down, and the blocks that are left sticking up make cliffs. Mountain ranges so made have long, gentle slopes on the side opposite the cliffs. Then there are volcanic mountains. Fujiyama, the sacred mountain of Japan, is one of these.