Chicago : Engineering and Contracting Pub. Co. · leaf 106
. The firstbrought out was the duct formed and cov-ered at the factory with sheet iron, whichcover was later abandoned on account of itsshort iife and the difficulty encountered in cut-ting the material on the work into shortlength^. Later came the manufacture of this air to act as the form while… … tion takes place between the concrete and thelead cable, but my experience is that the ac-tion is so slight as not to be worthy of con-sideration. This class of conduit has not been generallyaccepted by the larger companies and it is rea- Rod Welded in End of Pipe j-Hex NutWeldedin End of Pipe…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
