Original linen-backed patent lithograph for F. Dumoulin's improvement of a shotgun trigger mechanism, one page, 14.25 x 9.75, February 2, 1898. The diagram depicts close-up cross-sections of the intricate inner workings of the trigger mechanism. The top border reads: "A.D. 1898. Feb. 2. No. 2696. Dumoulin's Provisional Specification." The lower border features the printed text: "Malby & Sons, Photo-Litho." The right border reads: "This Drawing is a reproduction of the Original on a reduced scale." In fine condition.