https://ggwash.org/view/68579/the-fascinating-story-of-dcs-aqueducts-and-reservoirs

An interesting story covering the history of aqueducts in and around Washington, DC. Anyone know where that tunnel image is from? (http://collections.si.edu/search/detail/edanmdm:nmah_1840608)As many of you know, the Georgetown Branch of the B&O served the Dalecarlia Reservoir which was fed by the Washington Aqueduct.