However, I wrote a letter the other day; it was to the bank. It informed them that I had arrived in London for a time and should be troubling them again shortly, London being to all appearances an expensive place. It also called attention to my new address--a small furnished flat in which Celia and I can just turn round if we do it separately. When it was written, there came the question of posting it. I was all for waiting till the next morning, but Celia explained that there was actually a letter-box on our own floor, twenty yards down the passage. I took the letter along and dropped it into the slit. Then a wonderful thing happened. It went _Flipperty-flipperty-flipperty-flipperty-flipperty-flipperty-flipperty- flipperty-flipperty-flipperty--FLOP._ I listened intently, hoping for more ... but that was all. Deeply disappointed that it was over, but absolutely thrilled with my discovery, I hurried back to Celia. "Any letters you want posted?" I said in an off-hand way. "No, thank you," she said. "Have you written any while we've been here?" "I don't think I've had anything to write." "I think," I said reproachfully, "it's quite time you wrote to your--your bank or your mother or somebody." She looked at me and seemed to be struggling for words. "I know exactly what you're going to say," I said, "but don't say it; write a little letter instead." "Well, as a matter of fact I _must_ just write a note to the laundress." "To the laundress," I said. "Of course, just a note." When it was written I insisted on her coming with me to post it. With great generosity I allowed her to place it in the slit. A delightful thing happened. It went _Flipperty-flipperty-flipperty-flipperty-flipperty-flipperty-flipperty- flipperty-flipperty-flipperty--FLOP._ Right down to the letter-box in the hall. Two flipperties a floor. (A simple calculation shows that we are perched on the fifth floor. I am glad now that we live so high. It must be very dull to be on the fourth floor with only eight flipperties, unbearable to be on the first with only two.) "_O-oh!_ How _fas_-cinating!" said Celia. "Now don't you think you ought to write to your mother?" "Oh, I _must_." She wrote. We posted it. It went _Flipperty-flipperty_----However, you know all about that now.