Tourniquets: strap-operated and screw-operated, for the arm and thigh. Engraving by J. Newton after E. Edwards, 1783.

Illustrates lecture to the pupils at the Maritime School, Chelsea, designed to impress on them the importance of using the tourniquet to avoid loss of blood on board ship. Above, tourniquet credited to "a French surgeon named Morell, at the siege of Besançon [1674]" (p. 29), using a wooden handle which twists and tightens a worsted cord. Below, the screw tourniquet, credited to Jean-Louis Petit, which has the advantage that it can be applied with one hand only: "Government has wisely directed every ship to be supplied with many screw tourniquets" (pp. 34-35)