Cost accounts for the fortification
Sums in ducats for moat, fortress walls, defensible walls and pillars under the rocca
Folio 33v is a densely worked sheet of cost accounts for the fortification, dominated by columns of multiplication and division and by running totals in ducats. Named entries include the removal of the hill (428 4/7 and 4662 6/7 ducats), the walls of the moats and of the fortress (640 and 1640 ducats, summing to 5942), the defensible walls (225), the terrain of the moats (918) and 300 ducats for three pillars under the rocca, tallying to 1818. Small red-chalk box figures represent wall blocks, and a footnote records a crossed-out 30 beneath one figure.
On this page
Running totals of the works, summed to 1818 ducats
The sheet gathers the costs of the fortification into tallies: the expense of the hill, the walls of the new moat (375 ducats), the defensible walls (225), the terrain of the moats (918) and 300 ducats for three pillars under the fortress, adding to 1818. A separate group sums the moat and fortress walls (640 and 1640) with 4662 to reach 5942.
Costed defences: fortress and moat walls, defensible walls, three pillars under the rocca
The entries name the defensive works being priced: the moat of the hill, the walls of the moats, the walls of the fortress, the defensible walls, and three pillars under the rocca. Each is assigned a figure in ducats.
Long multiplications and divisions behind the estimate
Around a red-chalk solid figure Leonardo carries out the supporting arithmetic, with sub-totals such as 300, 375, 225 and 918 gathered into 1818, and larger products worked below. A note records that a crossed-out 30 can still be read beneath one figure.
Excavating the moats' terrain (918 ducats) and building the walls
Among the priced items are the terrain of the moats, costed at 918 ducats, and the masonry of the new moat's walls at 375 ducats. These are the on-site earthwork and walling operations for the fortification.