Parapegm

Par"a*pegm (?), n. [L. parapegma, Gr. ?, fr. ? to fix beside; para` beside + ? to fix: cf. F. 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.