I just thought of the altar cloth. What is the basis for that?
I don’t know exactly, but maybe the altar cloth was originally in function a tablecloth. We do know that a symbolic meaning was later applied to it: as a symbol of the linen cloth Jesus was wrapped in. (That’s why Pope Sylvester in the mid-4th century decreed that the altar cloth must be of undyed linen, as was the original custom; at that time it became a fad among the recently-emancipated Christians to use rich material like silk or dyed cloths. Apparently, though, Pope Sylvester wasn’t heeded, or his decree didn’t get universal attention - by the end of the 4th century other bishops were still voicing their concern over over this, erm, liturgical abuse.)
Originally, there was actually no distinction between the corporal and the altar cloth that was spread over the altar. At first, the corporal was really this large piece of cloth - large enough at least that in 8th century Rome, two deacons spread it over the altar at the Offertory. So the corporal/altar cloth was used as a sort of tablecloth
and (folded) as a cover for the chalice. Eventually, the number of altar cloths multiplied, and the corporal became smaller so that it’s now more like a placemat than a tablecloth. And then the pall (a stiffened corporal) was invented as a cover for the chalice.
I’ve never heard of a portable altar stone but looked it up. I always learn something when I read your posts.
Pre-VII it was a requirement that a Mass be celebrated on a properly consecrated altar - one that had relics of saints in it. To solve the dilemma of how to celebrate Mass in a place other than a church,
portable altar stones were used. (
As this example,
this one and
this one shows, they were already used in the Middle Ages.)