


Newspaper Clipping Scrapbooks of Frederick Graff Jr., Chief Engineer of the Philadelphia Water Department. Part 2: 1858-1871

The Water and Drainage History of Philadelphia: A seven-part course

Half a Century of Clean Water

Grit Chamber, Essen, Germany

Sludge Presses for Grease Recovery, Bradford, England

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

A Day in the Ma’sh – Oil Refinery

Baldwin Locomotive Works
