Chicago : Engineering and Contracting Pub. Co. · leaf 538
Natural Surface -- Bottom of Excavation sides do not meet at the apex, but form anopening of 8 ins. next to each side of a wedge-shaped beam, running along the center line ofthe tanks. The openings allow the sludge set-tling on the sides to slide down into the sludge
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
