Ropes on pulleys, a labelled casing, and rectangular figures
Pulley tackle noted at the Cathedral's Holy-Nail hoist, plus a casing lettered n, a, b, m
Pen sketches of rope-and-pulley tackle fill the sheet, one of them tied to a memorandum about the pulley of the Nail of the Cross in the Cathedral. At the left a boxed casing holds a screw-like body with parts lettered n, a, b and m, to be inserted through an opening. Another rope on a pulley is marked simply "likewise," and two loosely drawn rectangular figures sit lower on the page.
On this page
Rope over pulleys
A block of pulleys reeved with rope is drawn at the top of the sheet. It is the first of two pulley studies on the page.
Memorandum: the Cathedral's Holy-Nail pulley
Beside the sketch Leonardo jots a reminder "in the Cathedral, at the pulley of the Nail of the Cross" ("In Domo alla carrucola del chiodo della Croce"). It points to a real hoisting mechanism he meant to observe.
A casing lettered n, a, b, m
A boxed casing (custodia) holds a screw- or spindle-like body, its parts marked n, a, b and m. The note directs that the body n m be put in through the opening or vent.
Another rope on a pulley
A second rope-and-pulley run, at the right of the sheet, is annotated only "likewise" (Item), referring back to the first pulley study.
Two indeterminate rectangular figures
Two loosely ruled rectangular figures, left unresolved, are sketched toward the foot of the page. The caption itself calls them indeterminate.