This 1907 photograph documents the construction of the steel-hulled vessel 'Prometheus,' its keel laid on September 18 of that year, as recorded on the placard at lower left. Shipyard photographs like this one were routinely commissioned to mark construction milestones. The heavy timber cribbing, steel gantry crane, and overhead wire network are characteristic of early 20th-century American shipbuilding practice. Project: 218494