During research for this blog I come upon interesting persons. This is the first.
JEAN CLAUDE ELÉONORE LE MICHAUD D'ARCON
Born, 18th November, 1733 at Pontarlier.
Died, 1st July 1800, aged 67 years, at Belfort.
His father wanted d'Arcon to follow an ecclesiastical career but from childhood he had a passion for arms.
He enrolled at the Royal School of Engineers at Mézieres in1754, qualifying the following year. He distinguished himself in the Seven Years War, particularly in the defence of Cassel in 1761.
D'Arcon is of interest for two reasons. First, he had a good career in military engineering, he had views and opinions; he published several works that were influential. Second, he was the leading French engineer at the Great Siege of Gibraltar, 1779 - 1783.
First - his career and his views. He was committed to the defence of the borders of France, he was very conservative, pro-Vauban in his approach. He published nine books, four of which were arguing for the Vauban bastioned fortifications. His main opponent was Montalembert who was arguing for casemates, caponniers and detached forts. To conclude, in the short term, d'Arcon won the argument and had a great influence on the Jacobin Government, arguing that Vauban's work, eg Lille, had allowed Revolutionary France to survive early defeats and that invading forces were held back under Vauban ramparts. In the longer term, the ideas of Montalembert won, particularly with France's enemies.
Second - Gibraltar. The Great Siege of Gibraltar was started by the Spanish armed forces in 1779. They did not meet with much success. In 1782, the French took over, under Marechal de Crillon with Colonel d'Arcon on his engineering staff. The siege on the land side had reached stalemate, so d'Arcon put forward a design for floating batteries to break the sea defences. Ten floating batteries were constructed a total of 212 guns, 5,260 officers and men. The batteries' artillery pieces were on one side of the vessel, with a counterbalance on the other side, had extra very stout timbers attached to the artillery side as protection and were rigged with sails to manoeuvre them into position. On 13th September 1782 the batteries sailed to the seaward defences of Gibraltar and a great artillery duel began at around 10.00 hrs. Simultaneously the Spanish started a bombardment on the land side from another 200 artillery pieces. The exchanges lasted all day. The British were firing red hot cannonballs and they succeeded in setting fire to the two largest floating batteries. D'Arcon's strategy went downhill from there. The French and Spanish had failed. The siege lasted until 2nd February, 1783.
D'Arcon also worked on some of the French border fortresses, such as Fort Dauphin. There is a very good 3D drawing of a Lunette D'Arcon on www.militaryarchitecture.com.
My thanks to Wikipedia, to Rene Chartrand for the detail ("Gibraltar 1779 - 83 The Great Siege" Osprey Publishing) and to Christopher Duffy ("The Fortress in the Age of Vauban and Frederick the Great").