Chicago : Engineering and Contracting Pub. Co. · leaf 473
Fig. 5—Steel Shoe Used for Ventilating Shaft. to the lower seam. This section measures 17ft.Xll ft. 4 in. in the clear on the center lines• if the axes, and has a depth of 100 ft. from … !
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
