Illinois Society of Architects · Chicago · leaf 171
167 … ARCHITECTS-In preparingplans and specifications for largebuildings should provide for an Automatic Private Branch Exchange The space occupied by this type of ap-paratus is much smaller than is required fora system using operators and for this reasonas well as on account of eliminating theoperator,…
Architecture · Building · Architects
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Telephones and telegraphs: 1902 : [and Municipal electric fire alarm and police patrol systems] (1906)](https://img.insideoutlibrary.com/img/200/ia-cu31924022817674-68-27.webp)
