Water's perpetual circulation and a plan for a book on water
The sea rising to the mountains like blood, and an index of books on ships, canals and rivers
The left leaf (58v) carries a lyrical account of water's endless circulation: driven against its own weight as blood is, it rises from the depths of the sea to the mountain summits, pours out through broken veins, and returns to the sea, wheeling continually between within and without, and, like a mirror, taking on the nature of every place it passes. The right leaf (45r) sets out an index for a projected treatise on water, an enumerated list of "books" covering ships' hulls, keels and rudders, siphons, the meeting of currents, weirs, riverbanks, navigable canals crossing rivers, and the silting and clearing of river beds.
On this page
The perpetual circulation of water, likened to blood
The cause that moves water through the veins against its weight is the same that raises the humors in all animate bodies; so from the sea's depth water rises to the mountain tops and, finding its veins broken, pours out and returns to the sea. He likens it to sap rising in a pruned vine and to blood rising and falling, wheeling in continual revolution between within and without.
Water as a mirror taking the nature of all it passes
Never at rest in course or substance, the water rises by accidental motion and descends by natural motion. As a mirror transmutes into the color of the objects before it, the water has nothing of its own but takes all, changing into as many natures as the places through which it passes.
Books on canals, weirs and riverbanks
The index outlines studies of embankments set across rivers, shallows beneath weirs, the twists of currents, the sites from which to draw water, the permanence of riverbanks, navigable canals led over or under crossing rivers, lands that drink canal water, and the clearing of silted river beds.
Index of a projected treatise on water
The right leaf is a numbered list of "books," running through hull concavity, side curvature, rudder placement, keels, water in vessels with air, siphons, confluences, and the shapes that impede water's course. The numbering restarts and repeats (a 12 appears twice), showing a working outline rather than a finished plan.