There are many places called Telegraph Hill that used to be semaphore towers.
dredmorbius · 28m ago
That would include the one in San Francisco, with which some readers may be familiar.
ttoinou · 5h ago
It’s also fascinating this didn’t existed 300 years sooner (with more towers because of poorer telescopes). Communication of information across a kingdom is so important
trhway · 3h ago
If i remember correctly the laser optical transmission tech started as a "laser visual telegraph" between 2 PARC buildings rooftops in the Stanford Research Park here.
anthk · 4h ago
Ah, so that's the origin of semáforo in Spanish, which the current meaning is
"traffic light". And a semaphore on programming, too.
[1] https://wiki.lspace.org/Clacks