The Analytical Authentication of Brass

As an example of how this type of information can help in the study of scientific instruments, we present two previously unpublished case studies. One relates to some instruments from the Barberini Collection, now in the National Maritime Museum, London, and one relates to two 18th Century English clocks by famous London makers (Tompion and Graham) from a private collection. 

The Barberini Collection comprises 24 various scientific instruments, supposedly put together by the Barberini family in Florence - particularly Maffeo Barberino (1568 1644), later Pope Urban VIII, and more particularly Cardinal Francesco Barberino (1597-1679). Unfortunately, only one piece of this magnificent collection can be definitely traced back to Francesco Barberino -a large concave burning mirror. The first complete list of the collection dates only to the First World War, and it was purchased by Michel and Landau of Paris in the 1930s, and some of it was exhibited at the Descartes Exhibition at the Bibliotheque Nationale in Paris in 1936. The complete collection was finally purchased by the National Maritime Museum in 1949 (Shaw, 1973). 

Only part of the collection was analysed at the Research Laboratory for Archaeology in Oxford - five examples were chosen, as follows (descriptions from Shaw, 1973)  

47/46-230C (860). Large Astrolabe, probably Italian. 41.5 cm diameter, in original case. Unsigned and undated, ca. 1630. 

10/47—216C (883). Sector. Brass, 19 cm length. Signed I Galli s fecit. Undated ca. 1600. 

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