Billy thought intently for a moment. He knew he had heard something about clouds and mist and heat and cold, but for the life of him he couldn’t remember when anybody asked him. That is what makes examinations so hard. You know, but you can’t remember. “Ah, ha!” said Nimbus. “You can’t think, can you? Well, I’ll tell you, and you’ll never forget this reason. The other day, when their mothers were all sitting and sewing, the Cloud children----” “What are their names?” asked Billy. “Well, there happened to be Pinkie Pink-Cloud and Goldie Gold-Cloud and Pearlie Pearl-Cloud. They asked their mothers if they could float over Central Park and watch the Earth children at play. Their mothers said yes, so away they went. At first it was great fun to watch, for it was Mayday and all the children were marching about in their pretty white dresses while nursemaids and fräuleins and mademoiselles by the dozen, and a few mothers, were looking on. “Then Pinkie and Goldie and Pearlie began to play tag among themselves, nor was it very long before Pinkie said that Goldie did not tag her when she said she did, and Pearlie took sides; so in one moment those little sunny faces grew black with anger and presently they began to cry as hard as ever they could.” “Well?” said Billy, as Nimbus paused. “Well,” repeated the Fairy, “don’t you see? Their tears were rain!” “Oh!” said Billy. “The next thing that happened was that their mothers looked up from their sewing and saw the dark spot over the park, where, a few minutes ago, it had all been bright and sunny. They knew what had happened, for in April and May the Cloud children are easily upset and cry if you poke your finger at them. So they floated over to the park and, instead of asking the children what the matter was, as most mothers would have done, Mrs. Gold-Cloud told the children to look down at the park.” “And what did they see?” asked Billy, who never before had thought of looking at the Earth children through the eyes of the clouds. “Why, the rain spoiling all the pretty white dresses and the children all stopping their play and rushing about for shelter.” “I know,” said Billy. “I was there myself.” “Were you?” said Nimbus. “Then you know what happened.” “I only know it stopped raining,” said Billy. “But don’t you know why?” asked Nimbus. Billy shook his head.