Loaded rods and the double rod balanced by cords
Since a-n is one-sixth of a-m, a weight of 8 at n leaves two-thirds of a whole at m
Continuing from the preceding sheet, these notes and diagrams distribute weights along single and double rods held by cords, computing how much each support bears. One worked case reasons that, since a-n is one-sixth of a-m, a weight of 8 placed at n lifts 8/6 (one and one-third) at m, leaving two-thirds of a whole there. The lower half of the sheet carries further mechanical drawings, a graduated beam and an arched, multi-support structure that the Ambrosiana catalogue tags as a wheel, lantern-pinion and millstone, together with a faint red-chalk sketch of a head.
On this page
Weights carried by a single rod on its cords
A rod hung with weights is analysed cord by cord, the diagram marked with fractions such as 1 3/5 and 2 2/5 to show the share each cord bears. The note breaks off asking 'how much the one cord toward...' as it compares the pull on the several supports.
Why a weight of 8 at n leaves two-thirds of a whole at m
For a double rod, Leonardo reasons that because a-n is one-sixth of a-m, a weight of 8 at n removes 8/6 at m, which is one whole and one-third. There therefore remains at m two-thirds of a whole, the balance of the load worked out as a proportion.
Mechanical drawings on the lower sheet
Below the statics diagrams the sheet bears further mechanical drawing: a long graduated beam and an arched structure carried on several supports. The Ambrosiana catalogue identifies a wheel, lantern-pinion and millstone among the figures on this leaf.