This patent-syndicate certificate, numbered 009 and covering 17 shares in the name of Mestelan Ernest (1 July 1908), concerns the bi-metal patents of Édouard Martin, an industrial technique linked to the assembly or treatment of bimetallic metals. Patent syndicates were, at the beginning of the 20th century, a common mechanism for financing innovation: investors bought shares in intellectual-property rights, hoping to receive the royalties generated by the commercial exploitation of the invention. This practice contributed to the industrial development of the Belle Époque. This document stands out for its particularly original theme — collecting patent-related securities is a very underexploited niche of scripophily — and for its very low number, indicating an early issue. It will interest enthusiasts of French industrial history and the history of intellectual property.