With that Paddy swam over to the place where he had cut the trees for his dam, and his heart was light, for he had long ago learned that the surest way to be happy is to be busy. CHAPTER X Paddy Starts His House. Jerry Muskrat was very much interested when he found that Paddy the Beaver, who you know, is his cousin, was building a house. Jerry is a house-builder himself, and down deep in his heart he very much doubted if Paddy could build as good a house as he could. His house was down in the Smiling Pool, and Jerry thought it a very wonderful house indeed, and was very proud of it. It was built of mud and sod and little alder and willow twigs and bulrushes. Jerry had spent one winter in it, and he had decided to spend another there after he had fixed it up a little. So, as long as he didn't have to build a brand-new house, he could afford the time to watch his cousin Paddy. Perhaps he hoped that Paddy would ask his advice. But Paddy did nothing of the kind. He had seen Jerry Muskrat's house, and he had smiled. But he had taken great pains not to let Jerry see that smile. He wouldn't have hurt Jerry's feelings for the world. He is too polite and good-natured to do anything like that. So Jerry sat on the end of an old log and watched Paddy work. The first thing to build was the foundation. This was of mud and grass with sticks worked into it to hold it together. Paddy dug the mud from the bottom of his new pond. And because the pond was new, there was a great deal of grassy sod there, which was just what Paddy needed. It was very convenient. Jerry watched a little while and then, because Jerry is a worker himself, he just had to get busy and help. Rather timidly he told his big cousin that he would like to have a share in building the new house. "All right," replied Paddy, "that will be fine. You can bring mud while I am getting the sticks and grass." So Jerry dived down to the bottom of the pond and dug up mud and piled it on the foundation and was happy. The little stars looked down and twinkled merrily as they watched the two workers. So the foundation grew and grew down under the water. Jerry was very much surprised at the size of it. It was ever and ever so much bigger than the foundation for his own house. You see, he had forgotten how much bigger Paddy is. Each night Jerry and Paddy worked, resting during the daytime. Occasionally Bobby Coon or Reddy Fox or Unc' Billy Possum or Jimmy Skunk would come to the edge of the pond to see what was going on. Peter Rabbit came every night. But they couldn't see much because, you know, Paddy and Jerry were working under water.