Diagram Showing Rate Between Bulk of Wet Sludge and Its Percentage Moisture
Sludge Drying Beds, Essen Nord, Germany
Effects of Expansion of Gas Bubbles in Enscher Sludge Shown in Right-Hand Cylinder
Water, Water Everywhere – Philadelphia Record, 1937-03-14
Frankford Creek: Sad History of an Urban Stream title page
Outhouse over the Schuylkill near Pottstown
Pegg’s Run, Northern Liberties (Watson’s Annals)
Swimmers at Pier 126, Delaware River, July 15, 1918