Parapegm
Parapegm , noun
[Latin parapegma, Greek {not transcribed}, from {not transcribed} to fix beside; para` beside + {not transcribed} to fix: compare French parapegme.]
An engraved tablet, usually of brass, set up in a public place.
Parapegms were used for the publication of laws, proclamations, etc., and the recording of astronomical phenomena or calendar events.