The Rise and Fall of the Visual Telegraph (2017)

For the discworld alternative, check the clacks [1].<p>[1] <a href="https:&#x2F;&#x2F;wiki.lspace.org&#x2F;Clacks" rel="nofollow">https:&#x2F;&#x2F;wiki.lspace.org&#x2F;Clacks</a>

There are many places called <i>Telegraph Hill</i> that used to be semaphore towers.

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

If i remember correctly the laser optical transmission tech started as a &quot;laser visual telegraph&quot; between 2 PARC buildings rooftops in the Stanford Research Park here.

Ah, so that&#x27;s the origin of semáforo in Spanish, which the current meaning is &quot;traffic light&quot;. And a semaphore on programming, too.