Subjects Urban Development

Black-and-white image of two cylinders on a white surface

Effects of Expansion of Gas Bubbles in Enscher Sludge Shown in Right-Hand Cylinder

Black-and-white photo of heavy machinery

Sludge Presses for Grease Recovery, Bradford, England

Black-and-white image of a tray with three compartments and four small glass cylinders

Drain water from sludges obtained from sedimentation, septic and Emscher tanks

Black-and-white line graph showing two jagged lines on a grid

Diagram Showing Decreased Amount of Dissolved Oxygen in Delaware River, 1913

Black-and-white image of a brick sewer outlet that drains into a creek with trees and a hill behind it

Thomas Run sewer outlet at Cobbs Creek

Water, Water Everywhere – Philadelphia Record, 1937-03-14

Black-and-white image of a refinery with smokestacks emitting smoke

A Day in the Ma’sh – Oil Refinery

Black-and-white image of workers in a pit with a sewer opening behind them and text

Frankford Creek: Sad History of an Urban Stream title page

Outhouse over Schuylkill near Pottstown

Outhouse over the Schuylkill near Pottstown

Baldwin Locomotive Works, 1884

Baldwin Locomotive Works

Pegg's Run

Pegg’s Run, Northern Liberties (Watson’s Annals)

Swimmers at Pier 126, Delaware River July 15, 1918

Swimmers at Pier 126, Delaware River, July 15, 1918