Mechanical studies: bar-cutter, pump and Heron's fountain
A toothed cutting tool, a pump cross-section, a water-motion note and a bearded profile
A densely worked sheet gathering several mechanical inventions in pen and ink: a circle and circular ring labelled a and b, a large toothed bar-cutter (troncasbarre) resembling a pair of pincers with a serrated jaw, and a cross-section of a pump marked for water and air. Set upside down within the page is a note on Heron's fountain asserting that incident motion is always stronger than reflected motion, and blocks of arithmetic run down the centre. At the upper left a lightly drawn bearded profile head stands apart from the machinery.
On this page
Bar-cutter (troncasbarre) with self-driving saw
A toothed cutting device is drawn at the lower part of the sheet, labelled a. The note explains that its position, between the middle and the third, lets it turn about through the squares, with revolving motion and teeth set one way. The saw must be twisted by force so that it drives itself, and kept small enough to fit into a flask.
Circle and circular ring, labelled a and b
On the right face of the sheet Leonardo draws a circle together with an annular ring (corona circolare), its parts keyed to the letters a and b. A cluster of small concentric rings nearby appears to work out the same form at reduced scale.
Cross-section of a pump
A sectional drawing of a pump is annotated to distinguish its chambers, labelled water, water and air. The layering of water and air marks how the mechanism separates the fluid columns within the pump body.
Heron's fountain and the note on motion
Drawn with the sheet turned upside down, a study of Heron's fountain carries the maxim that the incident motion is always more powerful than the reflected motion. The remark generalises the pressure-driven behaviour of the fountain into a rule about impelled versus rebounding movement.
Columns of calculation
Long strings of figures, including large multiples running into the millions, are worked down the middle of the sheet. They sit among the mechanical sketches as working computations rather than a continuous text.
Bearded profile head
At the upper left, apart from the machinery, a bearded old man is lightly sketched in profile with flowing hair. It is a figural jotting on an otherwise technical page and does not belong to the transcribed mechanical notes.