It had come. There was already quite a line of figures in each of their notebooks. Now they could see what this other record was like. As he left the post office he stopped to look at the old thermometer beside the door. Then he mounted Nell and rode down the village street and out into the pleasant country road. Uncle Robert was waiting for him on the porch, and as Donald rode away to the barn, after giving him the mail, he heard him say: "Here, Frank, is the Weather Report. Open it and look at it while I read my letters." Donald took off the saddle and gave the horse her supper. Then he hurried back to see what Frank had found on the inside of the important-looking wrapper. It proved to be a map with queer, crooked lines all over it, but it did not look at all interesting. "Here it says temperature," said Frank, pointing to a list of figures in the corner. "Perhaps this is what we want." "I don't see any numbers there like mine," said Donald, taking his notebook from his pocket. "Let me help you," said Uncle Robert, laying aside his letters and coming to where they sat on the steps. They made room for him, and, as he took the map, he explained: "This, you see, is a map of the United States. These dotted lines tell about the temperature. For instance, look at this one which is marked fifty degrees. At every place in the country that is touched by this line on the map the thermometer stood at fifty degrees at the time the map was made." [Illustration: United States weather map.] "See," said Susie, "how crooked the line is. Why isn't it straight, uncle?" "Because," was the reply, "as I told you, it goes wherever the temperature was fifty degrees. You remember, the first day we had our thermometer, we found that there are many things which affect the temperature. At some places along this line there are prairies, at others forests, at others lakes, and here," pointing to the map, "there are high mountains. All of these things affect the temperature, and that, of course, changes the direction of the line." "You say Chicago is the nearest station to us, uncle," said Frank, looking down the temperature column. "My record for that day is not so very different from the one given here for Chicago." "Which shows that yours is probably as nearly correct as this is," said Uncle Robert, with an encouraging smile. "But I haven't one number in my book like that," said Susie, looking disappointed. "I don't see why." [Illustration: Susie's notebook] "I do," replied Uncle Robert. "You make your record at noon, and of course, it is warmer then. That is what your book says, does it not?" "Yes," said Susie, "every number in my book is more than that one." "That is right," was the reply, "for this record was made at eight o'clock in the morning, which is nearer Frank's hour than it is yours. So we would expect his to be nearer like this than yours, wouldn't we?" "It isn't like mine either," said Donald.