So far from being merely an artistic mind Leonardo da Vinci had typically the scientific and inquiring mind. Whenever a scientific problem came up to him, no matter how others had solved it before him and above all no matter how his contemporaries were solving it, he solved it for himself and almost inevitably in the true light of science. For instance while he was engineer, in charge, to use our modern term, of the canals of central Italy, the cuttings necessary for them brought to light a series of fossils. These were mainly shells resembling the seashells of his time, though not exactly like them. Before this a number of such finds had been made and man had found it very hard to explain them. They were usually {23} uncovered beneath a rather thick layer of earth. They looked like shells that belonged to creatures that had lived on a seashore. How could their presence be explained far from the sea and completely covered up? Occasionally, when found near the surface on the tops of rather high mountains a distance from the sea, the explanation had been offered and generally accepted that they had been deposited there by the Deluge. The buried shells and especially those deeply buried could not be thus explained. Scientists, and let us not forget that it was scientists in the true sense of the term who were especially concerned with such objects, men who knew their mathematics and principles of science very well and who had made valuable observations in other departments of science, evolved a learned theory of their presence. These were incomplete beings occurring in the earth because of a surplusage of creative power that had not quite finished its work. Their development had been arrested as it were before they actually became living creatures. When Leonardo da Vinci ran across the shells in the cuttings for his canals, he suggested another and a simpler explanation as it seemed to him. These were actually marine shellfish, which had been deposited where they now were at a time when this portion of land was submerged by the sea. They had become covered during the process of sedimentation and transformation of the land which had gradually pushed the sea far away. It always requires a genius to offer so simple an explanation as that, and as a rule it seems quite out of the question to most of his contemporaries, because of its very simplicity. They usually express their disdain for such simple-mindedness or wrong-headedness rather forcibly, though after a time they come to accept the explanation of it, but usually refuse to give the inventor any credit for his idea, because it now seems so obvious that they cannot think of it as so very new, after all.