Hand coloured engraving; plan coupe D'une Cone = [plan and section of caissons used to construct the breakwater, with letter press text in English]. 433x306mm; 270x248mm plate mark. Both plates are French with the later imprint: "Pub as the act directs by I Breadhower June 28th 1787 Portsmouth". Printed on paper watermarked `J Buttanshaw'