Expert: William J Perkins - 5/19/2007

Question
We have a Seth Thomas crystal regulator that currently is running about 25 minutes too fast over the period of a week.  The pendulum has a small screw at the bottom that raises/lowers the weight which I assume will conversely speed/slow the time. If this is a correct assumption, which way should this screw be turned to slightly slow this clock down.  Right or left?  Thank you in advance for taking the time to answer this question.

Answer
Yes you turn the nut on that screw to regulate timekeeping.  It is called a regulating nut.  Turn the nut clockwise to raise (increase speed), turn it counterclockwise to lower (decrease speed).  I suggest you allow 12 hours after making an adjustment before trying again.  That should do it for you.  Regards WJP