Scale 1:32. Design model of Thompson's patent rudder, with a model of a common rudder for comparison. Both models are carved from ivory with the gudgeons and pintles made in silver. Thompson's rudder is complete with the stern post. Both rudders have been drilled at the head to take a tiller. Thompson's rudder is inscribed "Thompson's Patent Rudder. Scale of feet & inches. Deadwater relieving piece". Common rudder is inscribed "Common Rudder. Scale of feet & inches". Both models are in a red leather bound presentation box lined with red velvet with a push button locking device and brass hinges. On the outside of the lid is a blank silver plaque.