Chelsea 12" Marine Clock for Board of Education, New York City. The dial is also engraved American Steam Gauge & Valve Manufg. Company, Boston, Mass, USA. Additionally the dial is engraved Chelsea Clock Movement 7 Jewells. #985345 is stamped on the dial below 6. The oversize, early style, key locking case is case 14 3/4" in diameter and 3 1/4" deep. The movement is stamped Chelsea Clock Co. Serial number 83826 on the movement dates the clock to 1913. The case has been polished and lacquered. he dial has been resilvered. The movement has been overhauled. A very unusual large dial Chelsea marine clock.