Discussion on “automatic private branch exchange development in San Francisco” (Deakin), Portland, Ore., April 17, 1912. (see proceedings for April, 1912)

H. M, Friendly: I ask if Mr. Deakin has ever considered the use of a private branch exchange having a limit of 170 stations instead of the 90 station limit in order to obviate having to use second selectors. In Chicago, I saw the switch that the manufacturers had designed, but I had no knowledge of its practical use. I also saw one at Columbus, Ohio, they were testing. The switch differed somewhat from the ordinary connector switch known as ten levels up and ten horizontal. This switch had twelve levels up and nineteen levels horizontal, in that manner you could obtain one hundred and ninety terminals. Of course, 1 assume Mr. Deakin would have to kill the top terminal, that is the naught level in order to facilitate intercommunication. I would like to ask if that kind of equipment has ever been figured on, and if it has been successful?