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
Captain Sewer and Michael Nutter, 1998
30th Street Sewer
69th St. Sewer and Culvert across Lansdowne AVe.
Ventilating cover for manholes
Torresdale Conduit work gang, 12/18/1906
