ANTIQUE EBONY & BRASS PARALLEL RULE BY S.C. POTTER, POULTRY, LONDON. I COULD NOT FIND ANY S.C. POTTER IN ANY OF THE BRITISH REFERENCE BOOKS I HAVE BUT THIS RULE IS TOO WELL MADE TO NOT BE A MANUFACTURED PIECE. IT MEASURES 15" LONG. ALSO HAS AN IVORY INSERT ON ONE END FOR MAKING MARKS. HAS A SQUARE BRASS ATTACHMENT WITH N,S,E & W ON IT WITH DEGREE'S ON IT. I HAVE NEVER SEEN A PARALLEL RULE WITH THIS ATTACHMENT BEFORE SO IT MUST HAVE BEEN A CUSTOM ORDER OR CUSTOM MADE.
