London Brass Rubbing Centre.

Washington Cathedral, Wisconsin and Massachusetts Avenues NW.

Monday through Saturday,9 a.m. to 5 p.m.; Sunday, 9.30 a.m. to 5.30 p.m. 244-9328.

Medieval knights and nobility probably never imagined that the brass effigies they had commissioned for their tombs would be sought seven centuries later by commoners wanting to make "rubbing" of them. Now the London Brass Rubbing Centre has imported this popular British hobby to an area to stone archways in the undercroft of Washington Cathedral where people can choose from replicas of 45 English, Belgian and Scottish brasses (replicas are now used ot preserve the originals). The fee ($1 to $16) is determined by the size of the brass you choose to rub, which can be anything from a head to a full-armored or elabrately gowned figure. At the feet of the men's effigies you will usually find a lion, a sign of courage, at the women's feet, a dog, symbolizing faithfulness. A pamphlet describing the date and background of each brass is provided along with paper (black or white) and a beeswax crayon (silver, black, gold or bronze), and expert instruction. In half an hour you can walk away with an unusual wallhanging, a different kind of gift, of just a memento of the past.