Piombino Fortifications: Parapet, Covered Way, and Costs
Pricing the parapet and ditch, a covered relief-way to the ravelins, and the total of the works
Leonardo prices the defensive works of the Piombino fortress, reckoning the parapet above the landward wall at 225 ducats from its dimensions in braccia reduced to canne. He proposes an underground covered way from the citadel to the ravelin of the gate, entered by a drawbridge, so the garrison can relieve it even if the townspeople side with the enemy. A tabulated summary totals the tower, ditch walls, parapet and ditch at 2099 1/16 ducats, and a closing note adds the cost of leveling the mountain to reach a grand total of 2528 ducats. A small profile is sketched beside the cost table.
On this page
Parapet and a covered relief-way to the ravelin
The parapet above the landward wall is 2 braccia high and 6 thick over a length of 300, costing 225 ducats once reduced to canne. Leonardo would run a covered way (an underground mine or 'strada coperta') beneath it from the citadel to the ravelin of the gate, entered by a drawbridge. He fears the townspeople, if allied with the enemy, might break through it, hence the drawbridge safeguard.
Summary of the cost of the works
A tabulated account lists the tower at 585 ducats, the walls of the ditches at 343 3/4, the parapet at 225, and the ditch at 945 20/64. The sum of the fabric is 2099 1/16 ducats.
Leveling the mountain along the shore
Leveling the mountain amounts to 375 canne at 4 lire the canna, or 1500 lire, with an equal quantity remaining along the seashore, totaling 3000 lire, that is 428 4/7 ducats. Added to the 2099 1/16 already reckoned, this makes a grand total of 2528 ducats.
Profile sketch beside the accounts
To the right of the cost table a small pen profile is drawn, apparently a channel or ditch section, with the figure 10 written above it. It sits between the top text and the tabulated costs.