This one again! My 1892 CPR Waltham, 18-size railroad pocket watch. Set to the second 25 days ago, and hasn’t stopped since. Re-set minutes and hours only to MST at the time change, but seconds not disturbed. After the first 7 days, it had gained 20 seconds, but not re-set. Still 20 seconds fast after 14 days, so no change in the rate. Same goes after 21 days, no variation. On the 22 day, I forgot to wind it. On last Friday morning (the 23 day), I remembered to wind it. It hadn’t stopped but was 7 seconds slow. Today (the 25th day), still seven seconds slow! It is 108 years old and continues to amaze me! Freshly serviced and new mainspring in mid October.