Siemens: Berlin telephone exchange, 1900
Telephonic communication, another crucial component of the modern city, requires extensive infrastructure – including telephone exchanges where incoming calls are switched to the correct destination phone numbers. This original sales book was published in 1900 by Siemens and Halskie. Extensive photos depict pioneering advances in the refinement of the telephone exchange as seen in Berlin. Switchboards at the time were electromechanical and manned by more than a dozen operators. The wiring was so large and complex that one photo shows a person emerging from inside the switch under an umbrella of wiring that must have included a curtain of at least 5,000 separate wires. Another picture shows a group shot of people collected around what was then an uncommon sight, a telephone pole. In 100 years it will probably take a leap of imagination to conceptualize that for nearly a century, all telephone calls were carried on specially-treated dead trees with crossbars that had been placed in holes in the ground, specifically to hang the wires needed to connect two callers.