While on the plane, you begin conversing with a mathematician. After learning of your quest, he encourages you to find out about Leonardo of Pisa, later known as "Fibonacci." He tells you a story about the last time he was in Pisa:

"Last month, I flew to Italy to attend a conference in Rome. After the meeting was over, I spent a couple of days in Pisa, curious to learn how aware were today's inhabitants of that beautiful city of their famous predecessor - a man who quite literally changed the course of history.

A web search before I left told me that there was a street in Pisa called the Lungarno Fibonacci as well as a statue of the man, athough sources differed as to the statue's location, with one website even claiming that there are two statues. (There are not.)

The street was easy enough to find. It runs alongside the south bank of the Arno River at the eastern end of the city, adjacent to a delightful, if slightly run-down, little park called the Giardino Scotto, named after Leonardo's friend Michael Scott, the astrologer whom I have mentioned already, to whom Leonardo dedicated Liber Abaci.

But the statue proved harder to track down. According to some web sites, it was located in the Giardino Scotto, but that is not true. It turns out that it used to be there, but some years ago it was moved. Another web source referred to the statue as being located in a cemetery adjacent to the Piazza dei Miracoli, the beautiful, green-lawned area housing the Cathedral, the Baptistery, and the famous bell tower, the Leaning Tower of Pisa.

Now, there is a cemetery next to the Piazza dei Miracoli: a small Jewish cemetery at the north west corner of the square. But that did not seem to be a very likely location in which to find a memorial to the (presumably) Catholic Leonardo. And indeed, it is not there. So where was this statue?

I walked into the official City of Pisa Information Center at the edge of the square.

"Where is the statue of Leonardo?" I asked the woman sitting behind the desk.

"Leonardo Da Vinci?" the woman replied.

"No, Leonardo of Pisa," I answered.

The good lady, whose English seemed impeccable, looked at me as if I were from another planet. "Leonardo Da Vinci!" she repeated firmly, stressing the words "Da Vinci," clearly intent on correcting me.

"No, Leonardo of Pisa - Fibonacci." I tried to be equally firm.

The information officer clearly thought she was dealing with a complete imbecile. "There is no Leonardo of Pisa," she declared. "There is no such statue here."

It was clearly pointless pursuing this exchange. Leaving the information office somewhat frustrated, I took a second, and more thorough look at one of the tourist information signs posted around the square.

There are, it turns out, not three but four buildings that make up the religious complex of the Piazza dei Miracoli. In addition to the Cathedral, the Baptistery, and the Bell Tower, all begun around the same time in the middle of the twelfth century, there is a fourth building, the Camposanto. Its English name, the information poster said, was Monumental Cemetery. Aha!

The Camposanto was started in 1278, after the other three buildings were essentially completed. Compared to its three sisters, the face this fourth building presents to the outside world is unremarkable. Apart from an ornately carved Gothic tabernacle that rises up above one of the two large metal doorways that open out toward the Cathedral, all the visitor sees from the Piazza is a long, low, clean white stone wall. The Camposanto keeps its more discrete beauty hidden from the outside world, facing inwards, with four cloistered walkways looking onto a long rectangular lawn.

I entered the cemetery through the left-hand door, turned left and walked around the western end. And there, facing me, at the far end in front of the eastern wall, was the imposing statue of Leonardo Fibonacci. (Perhaps it would be more accurate to describe it as a statue to Fibonacci. There is no known contemporary drawing of Leonardo, so the statue may well be a work of pure fiction.)

The statue had started out in the Camposanto. Then it had been moved to the Giardino Scotto - to save it from possible damage during the Second World War, one source told me. (If so, it was a wise move, since the Camposanto was largely destroyed in 1944, and had to be extensively renovated.) After some years, exposure to the riverside weather started to take its toll on the statue, and eventually it was taken away, restored and cleaned, and then returned to its original location, alongside Pisa's other illustrious citizens, where it belongs. Less than fifty yards from the City of Pisa Information Bureau where the lady told me there was no such monument.

Well, the employees in today's City of Pisa information bureau might not know much about Leonardo, but the splendid location the statue occupies indicates that someone in Pisa, at least, recognizes his importance. As well they should."

(Excerpt courtesy of Devlin's Angle, Mathematician's Association of America)

You decide to try to find the statue yourself, but first, you scribble a question to yourself in your journal: What is the Liber Abaci that Leonardo of Pisa dedicated to Michael Scott? Click on the arrow to continue to the statue.