Topics Technology & Engineering

Three reports on Philadelphia’s Sewage Treatment Project, 1911-1914

Black-and-white photograph of a man in a hat standing in a brick trench

Grit Chamber, Essen, Germany

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