Leonardo DaVinci's drawing (from the year 1492) blends art and science and demonstrates his interest in the rules of proportion and attempts to relate man to nature. It correlates to ideal human proportions laid out in Book III of the treatise De Architectura by the ancient architect Vitruvius. Other artists tried to realize the vision, with less success. Vitruvius linked the principal source of proportion in the orders of architecture to the design of the human figure.