It was in 1955 that the Hafner Publishing Company of New York City brought out G. W. Dunnington's scholarly Carl Friedrich Gauss, Titan of Science: A Study of His Life and Work. I was teaching at the University of Maine at the time and, as I was then in the process of building up a history of mathematics library, I ordered a copy of the book. I keenly looked forward to the book's arrival, and was delighted a couple of weeks later to find it on my office desk, amongst an assortment of other mail, delivered there for me while I was in class. Since I had a free period, I sat down and began listlessly paging through the volume. Imagine my astonishment when I got to the facing pages 100 and 101 to find there four neatly pressed four-leaf clovers. What a mysterious surprise! For some days I pondered on the mystery and told a number of my colleagues about it. Many wild and unlikely conjectures were offered, like: perhaps the book company does this with all their books, or perhaps only with the Dunnington volume, or maybe only for new customers, and so on. Finally my friend Professor Wootton decided to order a copy of the book for himself just to see if he too would receive some pressed four-leaf clovers. In time his copy arrived. It contained no four-leaf clovers.