Scope and ContentThis pair of blueprints documents the standardized construction specifications for Arrington & Sims engine foundations, as used in late 19th-century industrial settings. Produced in January 1889, the drawings detail the structural design, dimensions, and installation layout for mounting steam engines on solid concrete bases. Included are cross-sectional views, top-down schematics, and an extensive dimensional table that lists measurements for various engine types. These documents were retained as part of Lewis H. Latimer’s working collection, reflecting the technical environment in which he operated as a draftsman and engineer. They offer valuable insight into the engineering standards and mechanical infrastructure supporting early electrical power systems during Latimer’s tenure with the Edison Electric Light Company.