Subjects 1914 Sewage Treatment Plan

Black-and-white image showing several cubic measurements of various types

Volume of Sludge from 1,000,000 Gallons of Sewage

Black-and-white photo of a man standing in a long trench

Sludge Drying Beds, Essen Nord, Germany

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

Grit Chamber, Essen, Germany

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 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 table with numbers in columns

Bacteria in Delaware River, Torresdale Filters, 1913