Credit List for Historic Images History page banner image | Waldo C. Twitchell, C our tesy Palace of the Governors Photo Archives (NMHM/DCA), PAMU249 Leslie B. Duke beside the crusher, Assay Lab, 1913 | Waldo C. Twitchell, C our tesy Palace of the Governors Photo Archives (NMHM/DCA), PAMU249