


Diagram from sewage treatment plan for Philadelphia, 1912

Centre Square Water Works, Drawings of Intake Basin

Centre Square Water Works, Frederick Graff, Sr. Plans, 1799

Centre Square Water Works, Latrobe Plans, 1799

Plan and profile of proposed Delaware Seventh St. Sewer, 1850

Plan of Pine Street Sewer, 1830

Fairmount and vicinity, 1839

Isometrical View of Fairmount Water Works, 1843

Steam engine drawing, Frederick Graff Sr., 1815

Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
