 
		 
		 
		PWD Drinking Water Treatment diagram
 
		Steam engine drawing, Frederick Graff Sr., 1815
 
		Fair Mount Water Works engine house, 1819
 
		Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
 
		PWD water tech at the Philly Home Show, 1960 (detail)
 
		State Street pipeline construction, 1904
 
		Belmont Filters construction, 1903
 
		Rudolph Hering
 
		Electric Pump Installations at Lardner’s Point Pumping Station
 
		View from the Inclined Plane near Philadelphia, 1838
