August Thonet (1829–1910) was the third-oldest son of Michael Thonet (1796–1871). From 1869 to 1890, he headed the Thonet factory in Bistritz in present-day Romania, which became the most productive of the Thonet factories under his leadership. This was mostly owed to the development of new models likely created under his aegis. Though his authorship cannot be verified, he was probably also responsible for the design of chair no. 51. It has often been said that the chair’s shape recalls the construction of an iron building. It consists of six bentwood components that are connected in an ornate manner: The backrest is made up of three pieces of bent wood, with the backrest’s outer arch leading into the front legs and the extension of the inner arch crossing over into the chair’s back legs. Two further bentwood parts complete one front leg each and the diagonal back leg, thus forming loops which carry the ring of the seat.