Ludovico’s marriage to Beatrice d’Este, a girl of little more than fifteen years, further isolated Leonardo from the court. Being almost a child, Beatrice loved parties and festivities, and she surrounded herself with people who catered to her frivolous whims. As a result so serious a man as Leonardo was forced into the background of the court life. He was called upon more and more to act as stage-designer while his more important work went unnoticed. Because these entertainments were easy for Leonardo to design, they did give him more time to work on his giant equestrian monument of Francesco Sforza. Working one day on the scaffolding surrounding the clay figure of his statue, Leonardo heard a knock at his studio door. “Come in,” he shouted as he climbed down. “The door’s open.” Three peasants cautiously entered the room and quickly took off their caps. One of them was holding a carefully wrapped bundle. “Master Leonardo, we have brought you some shells we found on a ridge of Monferrato. Remember, you asked us to bring anything we found that was unusual?” “Yes, Pietro. Thank you. Put them here on the table.” Leonardo opened the bundle. He smiled when he saw the shells. He remembered how, as a young boy, he had found seashells like these high in the mountains. Leonardo questioned Pietro and his companions as to where they had been found and under what circumstances. He gave them some coins and, when they had gone, he looked among his growing collection of notes and drawings on the shelves. It took some time for him to find what he wanted, for the pages were in such confusion. Finally, he sat down at the table with several of the sheets and, putting the seashells in front of him, he began to make notes. The shells were fossil shells but, thought Leonardo, their presence on the high mountains of Lombardy could hardly be attributed to the great flood as described in the Bible. In his notes, Leonardo cited the case of the cockle which, out of water, is like the snail. It makes a furrow in the sand and can travel in this furrow about three to four yards a day. By such means, he calculated, it could not possibly have reached Monferrato from the Adriatic in forty days (which was supposed to have been the duration of the flood)—a distance of 250 miles. Nor were these simply dead shells deposited by the waves—for the living creatures are recognized by being in pairs, and these in front of him had certainly been traveling in pairs. Consequently, they could have been left there only when they were alive and the mountains were covered by the primeval oceans. Moreover, Leonardo also described how living matter in prehistoric times fell into the mud and died, and how this mud, as the waters receded and years had passed, was changed into rock forming a mold about the fossil—literally making a cast of its original living appearance.