Chicago : Engineering and Contracting Pub. Co. · leaf 164
clay is exposed. With a rockso much fractured as the andesite, this con-dition is unsafe, and the exposed surface ofthe underlying clay should, therefore, be pro-tected from further disintegration. The high record for the month was madeby shovel No. 207, working 24 days in theCulebra district,…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
