Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually
Francis Metallic Surfboat Francis Metallic Surfboat The Francis Metallic Surfboat is a boat, currently housed at 130 West Center Street in Douglas, Michigan. It was listed on the National Register of Historic Places in 2015. It is one of two known surviving examples of its kind, one of the first type of coastal rescue craft used. The Francis Metallic Surfboat was designed by Joseph Francis, an inventor who specialized in inventing and constructing maritime lifesaving equipment. Francis constructed 137 of these vessels from about 1849 to 1857, of which 48 were used on the Great Lakes. This particular boat dates from approximately 1854,