[tangentstar]

The “dial” on a rotary phone broke the connection in rapid sequence a number of times corresponding to the number dialed. If your dial broke, you could place calls by “flashing” the “hook” the right number of times with pauses between.

[edgineer]

You could do the same with a touch tone phone, too.

[tangentstar]

Heck, you could do it with a pair of alligator clips at a punch down panel. The telco was fun before everything went digital.