Undetermined scale. The model shows Sir William Congreve’s proposal for driving a boat (1827) by wave power. Although it appears to be a solid hull, it has been hollowed out, and weighted, and so might have been used for practical demonstrations or tank-testing. A drum, mounted at the bow of the model, is fitted with ‘scoops’ which fill with water as waves break over them. This causes the drum to rotate, driving a pair of conventional paddle wheels, linked to either side of the drum and driven by geared wheels. The principle was described in detail in a contemporary journal, ‘The Mechanics Magazine’, volume 7, page 216.

Though ingenious, there is an obvious drawback to the idea in that one’s direction of travel would be governed entirely by the direction in which the tide was flowing. One’s speed of travel would also depend upon the prevailing force of the waves. The numbers painted on the deck, ‘27-47’, denote a catalogue number from the Museum of Artillery at the Rotunda, in Woolwich, London, the main repository for Congreve’s many design concept models, from which the NMM acquired the object.