Chicago : Engineering and Contracting Pub. Co. · leaf 427
re. The properminimum depths of ditches to be constructedthrough shifting soils, as sand or peat, can-not be so definitely decided. Thick sub-soilstrata of sand overlaid with denser soils ren-der ditch construction and maintenance ex-tremely difficult of accomplisment as the sandstrata invariably…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
