Interestingly, they made the ‘dial’ by a series of “make/breaks” duration 60/40 on the line voltage present, IIRC. You could actually dial number without the dial. Just toggle the handset holder switch in the same sequence. You had to have rhythm, though.
Another oddity. The dial tone was 90Hz, a frequency that had extremely low transmission properties across the physical wires to the phones. The lines we either weighted in frequency from 300-3000Hz (3kHz Flat) or psophometrically weighted around 1 kHz. Regardless, the 90 Hz ring tone didn’t pass through the wires. How did it get through? They used two tones, 250 and 340 Hz - when mixed together produce intermodulation products, one of which is 90 Hz. It is the human ear that is the
‘mixer’ and the brain perceives that one product the most because it’s the lowest. Neat, huh?