Over winter break Jesse Obert, WHC Digital World History Postdoctoral Associate, had the amazing opportunity to study California Gold Rush era ships housed at the Maritime Museum in San Francisco in collaboration with Peter Gavette and the Golden Gate National Recreation Area team! Jesse used his expertise in archaeometallurgy in preindustrial metal working to determine the composition and learn more about the production history of these vessels. Jesse used a portable X-Ray Fluorescence spectrometer on the ship's sheeting, rudders, and pintles and discovered that they were constructed of in a leaded brass-bronze hybrid alloy. The rivets, however, towards the front of the rudder are pure copper, which would have made them more malleable and ductile -- less likely to break under the pressures and pulls of the ocean. Jesse will be doing future studies with this material and other nineteenth-century ships in the Bay Area in the coming months! Through his work in public archeology, Jesse is helping the Maritime Museum preserve the cultural heritage of the city of San Francisco.
