In May of 1504, the Signoria complained to Leonardo that there had been no progress on the proposed paintings for their council chamber, even though he had already been partially paid for them. Accordingly, he was forced to sign a document that he must be finished by February of next year or refund all monies paid him. As was his custom he had made many preliminary drawings. Although he was well acquainted with horses he had again researched their anatomy and actions. Pages of rearing, frightened horses and men in combat covered his studio tables. On one of these pages there are sketches of the heads of a lion, some horses and a man—all with fierce expressions on their faces. Here Leonardo hinted at the comparative anatomy of expression in man and animal that Darwin was to write about almost four hundred years later. But the paintings could wait, for now the Arno River was in spring flood. The time had arrived to make the first attempts at diverting the river into its new course. Leonardo was again in the field supervising the work. There had been much opposition to Leonardo’s canal from both the army captains and the Signoria. It was called a whim and a crazy idea, but Piero Soderini and Niccolò Machiavelli were stubborn in their defense of Leonardo’s plan and they overcame all opposition to it. And indeed, the raising of the sluice gates was successful and the Arno actually flowed into its new bed. The tensions in the camp and in the Council of Florence were eased. The only sad person was Leonardo, for he had just learned of the death of his father. Leonardo felt the loss deeply. Outwardly, however, he only acknowledged the death of his father at a distance. Not only had Leonardo and his father drifted apart over the years, Piero left nothing to Leonardo in his will. His father’s other children quarreled among themselves over what money he did leave. Leonardo’s one friend in the family was Uncle Francesco, who was still living in Vinci. When he heard of his brother’s will, Francesco made out a will of his own and left everything to the nephew he loved—Leonardo.