I am surprised that this was accomplished using primitive electric motors, relays(?), and mechanical parts. This page[0] seems to have some better descriptions

I am surprised that this was accomplished using primitive electric motors, relays(?), and mechanical parts. This page[0] seems to have some better descriptions of how they worked. The device seems to operate using two relay driven escapements that seem to function similarly to today's stepper motors advancing a single step forward or backward. Step signals are generated by a set of circular contacts connected to the pen mechanism on the receiver. So when the pen is moved a degree a step signal is generated. [0]https://www.jmcvey.net/cable/elements/telautograph1.htm https://www.jmcvey.net/cable/elements/telautograph1.htm