Outline Map of the County and City of Philadelphia and Vicinity, 1883
Philadelphia the Manufacturing and Industrial Capital map, 1906
“Philadelphia Underground,” Jan. 29, 1961
1779 Revolutionary War-era map of Philadelphia and environs
Centennial Exhibition situation plan, 1876
Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
30th Street Sewer
Oak Lane Reservoir pipeline, 1904
Upper Roxborough filter beds under construction, July 1902
Electric Pump Installations at Lardner’s Point Pumping Station
