Folio 4a313dc8
Italiano
Illustrissimo Signor mio,
This is to report that the earth rampart raised at Piombino against the Florentine guns is insufficient in slope and cohesion. The angle of repose is too steep—men walk the crest and the sod cracks beneath their boots like stale bread. The Florentines will place a battery on the heights of Poggio ai Cappuccini and enfilade the line before our own guns can answer.
I measured the rampart yesterday in the rain. The clay is lean, mixed with sand that shifts when wet. The palisade behind the parapet is set too high; the merlons offer no cover to the musketeers when the enemy fires over the crest. The ditch is shallow, not half the depth I specified, and the counterscarp is already slumping.
The fault is not in the plan but in the execution. The overseers used prisoners who know nothing of earthworks, and the master builder, that fool from Siena, mixed the mortar with salt water from the port. The lime will not set. I ordered the section dug out and rebuilt with fresh water from the cistern at the Fortezza, but the work is slow. The prisoners are sick with flux from the stagnant ditches they dug.
I propose:
1. Regrade the rampart to a slope of one in three, not one in two. The earth must be laid in courses no thicker than a palm’s width, each tamped with the flat of a spade until it rings like stone.
2. Lower the palisade to breast-height. Let the men kneel behind it; they will not stand to fire in any case when the Florentines open.
3. Deepen the ditch by one braccio and reinforce the counterscarp with fascines bound in osier. The fascines must be green, not dry; the salt in the old ones has drawn the lime from the clay.
4. Pay the prisoners in wine, not bread. A drunk man digs faster and complains less than a starving one.
5. If the work cannot be finished before the next moon, then place a row of gabions along the crest filled with sand and straw. They will blunt the shot and buy time to complete the rampart.
The cost of the gabions is less than the cost of failure. The Florentines will not give a second chance to a wall that collapses under their first volley.
I remain,
Vostro servo, Leonardo
English
Most Illustrious Sir,
This is to report that the earth rampart raised at Piombino against the Florentine guns is insufficient in slope and cohesion. The angle of repose is too steep—men walk the crest and the sod cracks beneath their boots like stale bread. The Florentines will place a battery on the heights of Poggio ai Cappuccini and enfilade the line before our own guns can answer.
I measured the rampart yesterday in the rain. The clay is lean, mixed with sand that shifts when wet. The palisade behind the parapet is set too high; the merlons offer no cover to the musketeers when the enemy fires over the crest. The ditch is shallow, not half the depth I specified, and the counterscarp is already slumping.
The fault is not in the plan but in the execution. The overseers used prisoners who know nothing of earthworks, and the master builder, that fool from Siena, mixed the mortar with salt water from the port. The lime will not set. I ordered the section dug out and rebuilt with fresh water from the cistern at the Fortezza, but the work is slow. The prisoners are sick with flux from the stagnant ditches they dug.
I propose:
1. Regrade the rampart to a slope of one in three, not one in two. The earth must be laid in courses no thicker than a palm’s width, each tamped with the flat of a spade until it rings like stone.
2. Lower the palisade to breast-height. Let the men kneel behind it; they will not stand to fire in any case when the Florentines open.
3. Deepen the ditch by one braccio and reinforce the counterscarp with fascines bound in osier. The fascines must be green, not dry; the salt in the old ones has drawn the lime from the clay.
4. Pay the prisoners in wine, not bread. A drunk man digs faster and complains less than a starving one.
5. If the work cannot be finished before the next moon, then place a row of gabions along the crest filled with sand and straw. They will blunt the shot and buy time to complete the rampart.
The cost of the gabions is less than the cost of failure. The Florentines will not give a second chance to a wall that collapses under their first volley.
I remain,
Your servant, Leonardo
