Expert: Martin Meyer - 1/11/2008

Question
QUESTION: MY VIENNA WALL CLOCK IS A HE&CO.(MARK SCHUTZ) TYPE, I THINK ABOUT 1880/90 WITH 2 WEIGHTS AND 'SECONDS' DIAL.

IT SEEMS TO WORK FINE, EXCEPT THE HOUR HAND IS ABOUT 1/2 HOUR OUT OF SYNC WITH THE MINUTE HAND.  SO WHEN IT IS 7.00 THE MINUTE HAND IS CORRECTLY AT 12 BUT THE HOUR HAND IS MID-WAY BETWEEN THE 7 & 8 (SHOWING 7.30).  THE GONGS STRIKE OK ON THE HOUR AND HALF HOUR WHEN THE MINUTE HAND IS IN CORRECT POSITION.  HOW CAN I SYNCRONISE THE HANDS PROPERLY ?.

ANSWER: Hi Philip,
    The hour hand (unlike the minute hand) is a simple friction fit and can be moved forward or backward without affecting the minute hand or the strike mechanism. All you have to do is move the hour hand ONLY to line up with the correct hour when the clock strikes. Occasionally the hour hand is tight on its shaft, so move it gently so as not to break it.

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QUESTION: THE PENDULUM HAS AN ENAMEL SCALE AT THE BOTTOM OF THE SWING AND INDICATES A READING OF JUST A FRACTION UNDER 1 (ONE). IS THIS ABOUT NORMAL, I'M SURE WHEN I FIRST HAD THE CLOCK 8 YEARS AGO IT USED TO READ ABOUT 1 1/2 (ONE AND A HALF)?

Answer
Hi again Philip,
    The scale is a beat setting scale. Its purpose is to see if the clock is in beat, which is indicated by the distance that the pendulum swings to each side. For example, if the pendulum swings to the "1" mark on the left, it should also swing to the "1" mark on the right.
    The beat scale does not show the correct amount of swing. Different clocks, with different length pendulums, will swing in different amounts, so I can't tell you what is correct for your clock.
    It is entirely possible that your clock used to swing more widely in the past but, due to need of lubrication or wear in the bearings, now swings a lesser amount. I would have the clock lubricated if it needs it and, if it runs reliably, not worry about the amount of swing.
    As a side note, overswing is not desirable on a pendulum. The wider the swing, the more error the pendulum will produce. This is due to a complicated physics principle regarding the difference between the circular arc that a real-world pendulum swings, versus the cycloidal arc that a theoretical-pendulum would swing. In practical terms, the pendulum is most accurate when it swings in the smallest possible arc that will keep the clock running.