Timepieces, you know, are really machines for keeping track of the apparent movement of the sun. Here is a device, as simple as a sun-dial and much simpler than a clock, by which you can record the actual motion of the earth. Sprinkle the surface of the water in a bowl with chalk dust. On this, sift from a piece of paper powdered charcoal or pencil dust, so as to make a clean-cut band extending across the centre and over the edge of the bowl. In the course of several hours you will find that the black band has swept round from east to west, because the water has stood still while the bowl has been carried from west to east by the whirling world. ] According to this theory the earth was once a mere baby world like those white lumps, and grew by gathering in its smaller neighbors from time to time by the power of gravitation. The larger it grew the more particles of solid matter it could draw to itself. Then it drew larger masses, for with increased mass came an increased pull of gravity. In the same way the earth is still growing, for it is thought that the shooting stars or meteors we see at night are little planets being gathered in. II. How the Continents Came Up Out of the Sea And before I got to be myself at all, while I was still only a part of the big pebble called the Earth, your geography and I lay at the bottom of the sea. For ages and ages! This is one of the stories you will find in the literature of science, of how, along with North America, South America, Europe, Asia, Africa, and Australia--have I left out any?--I came to land and brought your geography with me. I remember hearing a pretty young lady say, once upon a time: "There," said she, "I'm through with geography forever!" You see, although she had passed with marks around 90, she still had the idea that geography is a book. You and I know, of course, that the real geography isn't a book at all. It's the world itself. PUTTING THE CONTINENTS ON THE GLOBE But there was a time when there was no land. It was all water, and the continents were lifted into their places, much as you model a continent in making a relief map; they were sketched out and then filled in. North America, for example. First of all up came that mass in the northeast in what is now Canada; the Laurentian Highlands, as they are called in your geography. They rose very, very slowly, you understand, only a few feet in a thousand years; for Nature has all the time there is and never hurries. These highlands (they are really granite mountains worn down), along with the other rock formations of our continent, are supposed to be the oldest land on the earth. The continents of Europe and the rest were born later. So you see Columbus didn't discover the New World at all; he really came from the New World and discovered the Old!