Newspaper Clipping Scrapbooks of Frederic Graff Jr.,Chief Engineer of the Philadelphia Water Department: Part 1, 1854-1857
Newspaper Clipping Scrapbooks of Frederick Graff Jr., Chief Engineer of the Philadelphia Water Department. Part 2: 1858-1871
Two reports on the state of the Schuylkill River, 1867
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