Original draft of three figures drawn in red, black, and green. Includes a body plan, profile with hull arrangement, and half-breadth views. Manuscript text that describes the plan and vessel's dimensions. This lines plan is most likely the original design of HMS 'Cynthia,' a 16-gun sloop of war that Schanck designed for the Admiralty and which proved the utility of the sliding keel, a retractable fin keel used on vessels to provide greater lateral stability and allowed navigation of shallow waters. Sliding keels were introduced to merchant and naval fleets by the author of this lines plan, John Schanck. The vessel participated in two notable events: the surrender of the Dutch fleet in the Vlieter Incident and the Capture of Alexander.
This is one of four plans that appear to be associated with an early developer of a Western sliding keel, naval architect and British Admiral, John Schanck (1740-1823). Lieutenant Schanck was stationed in Boston before the Revolution and his first experiment with sliding keels appears to be represented in this plan. The date of this and the other related sliding keel plans in Clark Collection is not clear.
