The Egyptians wrote on papyrus or carved their history in stone, but the Babylonians had neither papyrus nor stone. All they had were bricks. So they wrote on bricks before they were dried, while they were still soft clay. This writing was made by punching marks into the clay with the end of a stick. It was called _cuneiform_, which means wedge-shaped, for it looked like little groups of wedge-shaped marks, like chicken-tracks, made in the mud. I have seen boys’ writing that looked more like cuneiform than it did like English. The Babylonians as they watched their flocks by night and by day watched also the sun and the moon and the stars moving across the sky. So they came to know a great deal about these heavenly bodies. Did you ever see the moon in the daytime? Oh, yes, you can. [Illustration: Babylonians watching eclipse.] Well, every once in a great while the moon as it moves across the sky gets in front of the sun and shuts out its light--just as, if you should put a white plate in front of an electric light, the electric light would be darkened. It may be ten o’clock in the morning and broad daylight when suddenly the sun is covered up by the moon as by a white plate and it becomes night and the stars shine out and chickens, thinking it is night, go to roost. But in a few moments the moon passes by and the sun shines out once again. This is called an _eclipse_ of the sun. Now you probably have never seen an eclipse of the sun, but some day you may. At that time, and even to-day when ignorant people see an eclipse of the sun, they think that something dreadful is going to happen--the end of the world, perhaps, just because they have never seen such a strange sight before and do not know that it is a thing that happens regularly and that no harm comes from it. Well, nearly twenty-three hundred years before Christ, 2300 B. C., the Babylonians told beforehand just when there was going to be an eclipse of the sun. They had watched the moon moving across the sky and they had figured out how long it would be before it would catch up with the sun and cross directly over it. So you see how much the old Babylonians knew about such things. Men who study the stars and other heavenly bodies are called astronomers, and the Babylonians, therefore, were famous astronomers. The Egyptians worshiped animals; but it was quite natural that the Babylonians should worship these wonderful heavenly bodies, the sun, moon, and stars, and they did. The first king of Babylonia whom we know much about--and that much is very little--was Sargon I, who may have lived about the same time that the pyramids were built in Egypt.