Rare separately issued plan of Cherbourg.

The plan gives detailed information on the defences at Cherbourg in 1788, with the position of the forts, redoubts and the reach of their cannon and mortar; together with the placement and construction of the ‘Trucated Cones, or Conical Caissons’. These large wooden structures – some 170 feet in diameter – were being placed at the harbour’s mouth in order to narrow its entrance. The plan and the text below goes into considerable detail upon their construction and to how they were placed in the harbour.

Although not at war with the French at the time, the plan highlights England’s continued concern about the strength and defences of the French channel ports and their interest in French military technology.