THE TELEPHONE, FRAME BY FRAME
A small turn. A distant hello.
How a rotary telephone
places a call.
One imaginary call to 212, through a simplified mid-century Strowger exchange. Mechanisms are slowed down or sped up so you can see the story unfold.
Read the story, frame by frame
Before touchscreens, a small spring and a pair of copper wires could set a room of machinery in motion. This is one way a local call could travel through a step-by-step telephone exchange.
A note on the machinery
Telephone systems varied across countries and generations. This film follows the basic idea of a Strowger, or step-by-step, exchange. The short number, switching stages, and timings are illustrative. A real exchange contains more relays and selectors than are shown here.