Very handy, [ and ness is appropriately impressed. ] In Faerûn, there was magic that could achieve something close to the same effect, message and sending spells, sending stones—but they were out of reach for most people. Almost no one would ever see magic done, much less be able to do it themselves, or hold a magic item in their own hands.

Was your world very safe? I can't imagine these vanes staying up very long in a world ravaged by war and disaster, or industry dedicating itself to communication innovations when machines of war are needed.