'It is really very neat and nice,' said mamma; and by way of 'handsel' or 'good-luck' to the new post-office, she immediately bought six stamps, for which she gave a whole penny extra, though Leo explained that of course he did not expect that _usually_. 'I hope your rules will be kept,' said Marion who had been reading them over. 'The principal one is about paying at once. Well, of course, that's a very good rule. It is so easy to forget to pay for such little things, if one doesn't do it at once. And then about the time of closing every evening.' 'At eight o'clock--when I go to bed,' Leo said. 'I shall come round then for the last time and shut up.' 'But,' said Cynthia, '_supposing_ mamma wanted a stamp quite late at night. It might happen, you know, and that was to be the good of having a post-office in the house. And if you had locked them all up'---- 'I can't lock them up,' said Leo; 'there's no key.' 'Well then,' said Marion, 'I think you should make a rule that if mamma wants anything after eight, she should be allowed to have it, or if any one else does, they might too, if they got her to sign one of the papers. Of course it wouldn't often happen, but just in case.' 'Very well,' Leo agreed; 'I'll add on that new rule,' and so he did. All went well for some time. The stock, of stamps especially, was sold out several times in the course of the first week or two, and everybody paid regularly. Once or twice, it must be owned, Cynthia forgot to pay, and more than once or twice people forgot to mark down what they had taken. But Cynthia was always ready with her pennies as soon as Leo asked her, and except for this the money was all right. More than all right indeed, for one day a friend of his mother's made such big purchases that he was quite cleared out, and had to set off to the chemist's at once, and thanks to this and to other smaller profits, by the end of the first week he had gained threepence, and by the end of the second, twopence-halfpenny more. So Leo began to think his post-office a great success. But one morning he had a start. He had left all quite correct the evening before; the money was right, and he knew exactly how many stamps he had left, when he had made his last round, as he called it, at bedtime; but this morning, though the money was the same, the stamps were not; three penny ones were gone. [Illustration: One morning he had a start.] Leo counted them all over and over again, 'to be quite sure,' even though in his heart he had been quite sure from the first. Then he ran up-stairs to ask his mother if possibly she had taken them after he was in bed, and forgotten to mark them down. No, mamma had not had any. Leo began to look quite distressed. 'Don't worry about it,' said his mother. 'It's the first time anything has gone wrong. I will pay the threepence, dear. It has just been some mistake.'