Main Pumping Stations for Philadelphia Drinking Water
Diagram Showing Rate Between Bulk of Wet Sludge and Its Percentage Moisture
Water, Water Everywhere – Philadelphia Record, 1937-03-14
Perkiomen Water Supply Surveys, 1866
Map of Philadelphia showing Population in year 1920
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
“Sewer Crawlers,” January 29, 1961
1779 Revolutionary War-era map of Philadelphia and environs
