Red Herring? in The Clock & Pocket Watch Forum Posted July 15, 2015 · Report reply Hi, All.Have just bought my first clock movement to hopefully bring back to life. From what I have gleaned, it's French, c. 1880s, has a count wheel set-up for the chime, takes a size 18 key and has a small pendulum (approx. 15cm, top-to-toe). There doesn't seem to be a maker's mark, just a serial number - 13078 - on front and back and an enigmatic inscription, either 15dm, 15Am, or 15clm on the backplate. The "15" is stamped, the characters are engraved in italics. Would anyone have an idea what this actually says and, more importantly, what it might mean? I'd love to post pictures, but don't know how. Many thanks in anticipation.