Perhaps a few electrical engineers fully appreciate panels are each sub-divided into small sections re- of other exchanges, whose calls are received on "incom- the scope of the improvements which have been made ceiving one hundred sockets or "jacks," numbered ing trunk-lines," with the subscribers… … The system which has as any subscriber's lamp GENEEAL VIEW OF THE MULTIPLE SWITCHBOARD OF A TELEPHONE EXCHANGE. thus discarded the mag- is alight. It is the purpose of the pilot-lamp to serve as an addi- neto-generator and the station-battery is technically known as the "common- tional means of…
Patents · Automobile · Apparatus · Artesian · Explosive · Zinc · Great Britain · Horse power · Acetylene gas · Zinc ores · Scientific American · Motor car · High explosive · Building edition · Wrought iron · Gas engine
Internet Archive · Public domain (published before 1931). Free to use for anything.
