How does the melted snow get to the river? Have you ever heard of rivers that are under the ground? If such a river-bed were dry, what would it be? Have you ever seen a ravine? Is it anything like a cave? If the roof of a cave fell in, what would the cave become? If the sides of a ravine became worn down, what would it become? Think of ways in which the cave might be flooded when the snow melts in the spring. Do you know anything about the floods that we have nowadays? _The Flood_ Winter was almost gone. The air was getting mild and soft. The snow was beginning to melt, and the river was rising. All along the banks there were mountains of snow and ice. Huge masses of floating ice were carried along by the current. The Cave-men were watching the swiftly rising river. They feared that there might be a flood. The children were playing in the melting snow and wading in the water. Sharpeyes had just come from the ravine. This ravine was usually dry in summer, but in winter it was filled with snow. Now it was a deep, dark stream, with black and threatening water. All the ravines were pouring their waters into the river, which was rising rapidly. Where the banks were steep the river was narrow. There the water was deep, and large masses of snow and ice were carried along by the strong current. At the drinking-place the banks were low. There the river was wider and the current was not so deep and strong. Small masses of snow and ice were carried along by the current, but the larger masses became lodged on the bed of the stream. In this way the river was forming a dam. [Illustration: “_All day long the Cave-men watched the river_”] All day long the Cave-men watched the river, but at night they went back to the cave. There were dark clouds in the sky; so Firekeeper covered the fire with ashes, and they got ready for the night. All but Firekeeper were soon asleep. As she kept watch that night there was something that troubled her. It was not the roaring river. It was not the pouring rain. She had heard those sounds before. It was a sound that was new to her, and she wondered what it meant. It seemed to come from deep down in the cave, and sounded like rumbling water. She did not wish to frighten the clan, so she let them all sleep. She listened again. She still heard the roaring of the river. She still heard the pouring rain. Below it all she heard that strange muffled sound. It was coming nearer and nearer. She felt water trickling over her bed of moss and leaves. At first she thought it was the rain. She peered into the darkness, but saw nothing. She felt of the running water. It was coming from the cave. Then she called Strongarm. He quickly roused the people, and they hurried out of the cave. A moment more and it would have been too late. The water rushed up from the dark narrow passage and out through the mouth of the cave.