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A LITTLE SOMETHING WORTH KNOWING

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HistoryOne small ahaInvention or discovery

Semaphore telegraph · the visible signals used to convey messages

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HistoryOne small aha
Your new ahaVisible positions of arms or flags.

Optical telegraph stations relayed visible signals along a route. Source: Optical telegraph ↗

ahamoraReference ↗

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  2. 18He developed an influential movable-metal-type printing system in fifteenth-century Europe.RECALL
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