[LMB] OT: Backups using My Book Live
beatrice_otter at zoho.com
Mon Jun 28 08:16:00 BST 2021
---- On Sun, 27 Jun 2021 21:39:20 -0700 <mailto:kbarry at bitsofhistory.com> wrote ----
I'm pretty sure they had mirrors. Small ones at least. But I would imagine for an effective heliograph all you would need is something capable of reflecting light. A silver coated dish for example. And the Romans had mastered silver plating long before the timeframe of the book.
Glass mirrors were invented in, like the first century AD, so it depends on which timeframe you're talking about. But even so, those Roman glass mirrors were fairly crude and very expensive to make. Most mirrors were polished metal discs, usually bronze, tin, or silver. They were cheaper to make and lasted longer because they didn't break.
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