Or perhaps earlier, when telegraph operators simply
retransmitted the
copy. If "unattented" is the operative answer, then Edison in 1864
with his "repeating telegraph".
If it's not electrical, how about semaphores, smoke signals, flags,
laterns, drums, whistles, riders and runners?
I should have said "Ma Bell", now that I think of it. Pretty much all
of basic concepts of computer networking* can be found in Notes on the
Network. All that fancy stuff about routing, least cost methods,
network failures, hierarchies, network addressing? All in there from
way back.
And of course, the telephone network is still the largest.
* ARPAnet, for getting the lions share of credit for inventing the
computer network, mostly just invented (and implemented) packet
switching.
--
Will