Original linen-backed patent lithograph for Carl Zeiss's improvement of a lens, one page, 14.25 x 10.25, September 2, 1910. The diagram features two angles of the crescent-shaped lens. The top border reads: "A.D. 1910. Sep. 2. No. 20,475. Carl Zeiss' Complete Specification." The lower border features the printed text: "Malby & Sons, Photo-Litho." The left border reads: "This Drawing is a full-size reproduction of the Original." In fine condition.