The intricate studies by Leonardo Da Vinci and his notes on human anatomy (human science), nature (natural sciences), etc. fill his sketchbooks. Most, if not all, are from observation and experiments to better understand what he draws and paints, of both human and natural worlds, and the built world around him. We see his thinking through of volumes, forms, and perspective of architecture, but also the symbols and myths found in the religious and merchant worlds. His sketchbooks, and codices, are filled with sketches of his machine inventions for flight, for building cities, and for war.
Pen and ink, and red chalk.
Artist: Leonardo Da Vinci.