Despite the availability of theory for ship construction, British naval shipwrights still principally used precedent, trial and error to design and modify their ships. During the 1790s, professional private builders and naval officers raised interest in Bouguer’s Metacentre theory and in the construction of experimental vessels. Samuel Bentham, who had built and modified vessels in Russia, proposed to the Admiralty in 1795 to build seven experimental vessels – sloops and schooners – which became his immediate task before becoming Inspector General. He drew upon his understanding of mechanics and upon the ideas of other contemporary builders like F.H. Chapman in Sweden. Having longitudinal as well as transverse framing and bulkheads, they possessed great strength but were unusual in appearance. They used small timber and the principle of ‘interconvertibility’ of equipment. Completed in 1796–7, the vessels were sailed to Portsmouth dockyard to be valued for purchase into the navy. However, the yard officers condemned their difference from normal naval structures, claimed they possessed one quarter the durability and estimated their value at less than half that proposed by Bentham. Yet, on demanding and receiving answers to questions of procedure, in 1798 Bentham condemned the officers attempt to excite a ‘false impression’, their methods of gathering evidence and their sense of ‘impunity’. Trials, surveys and service thereafter gradually vindicated the vessels’ design. Indeed, in 1804, to the chagrin of the Navy Board, the Inspector General was encouraged by the Admiralty to contribute to frigates building in the dockyards.