Calamine brass slowly phased out as zinc smelting techniques were developed in Europe, which produced metallic zinc more suitable for brass production than calamine. However, the conversion away from calamine brass manufacture was slow; a British patent was awarded to William Champion in 1738, but the alloying of metallic zinc and copper to produce brass was not patented until 1781 (by James Emerson), and calamine brass mills persisted in South Wales until as late as 1858. The slow diffusion of this technology was probably the result of economic factors. Calamine brass Calamine brass is brass produced by a particular alloying technique using
Schlangenberg Nature Reserve the interest in the ore which was mostly used for weapons and vessels. The greatest interest in calamine had been in the 18th century when brass manufactures settled in Stolberg (Rhineland). For the production of the alloy they needed large amounts of calamine which was melted together with copper. Before 1800 digging small reaching only surface based ore was the only technique available to the miners. In the 19th century mining changed and more than 20 adits enabled the workers to reach calamine up to 105 m below the surface. During this time the Schlangenberg-area was perforated like a Swiss