Group 12 element have zinc in its active site. In 1817, cadmium was discovered in Germany as an impurity in zinc carbonate minerals (calamine) by Friedrich Stromeyer and Karl Samuel Leberecht Hermann. It was named after the Latin "cadmia" for "calamine", a cadmium-bearing mixture of minerals, which was in turn named after the Greek mythological character, Κάδμος Cadmus, the founder of Thebes. Stromeyer eventually isolated cadmium metal by roasting and reduction of the sulfide. In 1927, the International Conference on Weights and Measures redefined the meter in terms of a red cadmium spectral line (1 m = 1,553,164.13 wavelengths). This definition has since
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,