Aluminia Day of Constituion Plate 1849-1915. Beautifully decorated. It has decoration number 1090/918. Diameter 22.5 cm. Perfect condition. In the 1880s when production at the Royal Copenhagen factory was dropping to a dangerously low level they were taken over by Aluminia (founded 1863), successful makers of earthenware, and since that time the two ranges, earthenware and porcelain, have been running in tandem.