Fourth of July, Centre Square, ca. 1812
Centre Square Engine House, ca. 1807
Roman Aqueduct in Segovia, Spain
Emscher Tank Installation at Essen Nord, Germany
Grit Chamber, Essen, Germany
Sludge Presses for Grease Recovery, Bradford, England
Drain water from sludges obtained from sedimentation, septic and Emscher tanks
Thomas Run sewer outlet during construction
Dobson’s Mill, 1884, from History of Philadelphia by Scharf & Wescott
A Day in the Ma’sh – Oil Refinery