Model, of navy frigate stern, fitted with Crispin's patent 1860 screw propellor
1861
Model, stern of British Navy steam frigate, fitted with Crispin's 1860 patent No. 2001 twin flat blade screw propeller, fitted to mahogany stand; plus a propeller inscribed with: ‘B’; and another propeller inscribed with: ‘C’, by William Crispin, Stratford, Essex, England, 1861