Typhoid bacteria diagram, 1905
Fairmount and vicinity, 1839
Steam engine drawing, Frederick Graff Sr., 1815
Lab tech, water cleaning demo, Philly Home Show, 1960
Bureau of Water Spring Garden Testing Station, 1901
River herring from the Schuylkill
Jar of raw sewage before treatment, 2000
Plan for the Collection, Treatment and Disposal of Sewage, 1914