Map of the County of Philadelphia from Actual Survey, 1843
“Philadelphia Underground,” Jan. 29, 1961
Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
30th Street Sewer
Torresdale Conduit work gang, 12/18/1906
Bureau of Water, Cumberland, west of 13th Street, pipe line, 1907
Oak Lane Reservoir pipeline, 1904
State Street pipeline construction, 1904
Finished Upper Roxborough filters, 1903
Upper Roxborough filter beds under construction, July 1902