This photo was taken in late 1982 or early 1983.
Originally, I had no intention of building a cabinet for the movement as I had a stand that I used for testing clocks that I had repaired.
Almost immediately, I learned that ordinary air currents in the room would disturb the pendulum. This made accurate timekeeping impossible, even though this pendulum weighs 28 pounds. Those 4 chrome plated tubes are completely filled with lead.
I had a quantity of maple woodwork and trim that I had salvaged from a house being torn down. This case was built using casings and cornice molding from around doors.The house had been built in the 1880s.
The dial had been the lid of a 55 gallon drum, the pendulum tubes were for kitchen drains and the pendulum shaft was an extra curtain rod I found in the basement of our house. The only purchased items were:
- the glass for the cabinet
- 10 inches of copper drain pipe for the weight shell
- paint for the dial
- tubes for the pendulum tubes
I was disappointed with the accuracy at first until I purchased a RadioShack TimeKube which received time signals from the U.S. Navy.
Then I learned that the inaccuracy was with the electric clock I had used for comparison.
One three week period, when the temperature varied only slightly, this clock stayed within one and a half seconds of the National Bureau of Standards time signals.
Our house at the time was a quite sturdy Victorian Italianate style. It was built using balloon frame construction and a brick veneer. The load bearing wall on which this clock was mounted rested on an 8X8 oak timber sill. The sill in this area was directly above a steel post that extended to a concrete footing I had poured during prior basement repairs.
Because I have never been able to duplicate that original accuracy in any building since that house, I have learned just how crucial a stable mount is for the pendulum,
Turning my attention to reducing friction, this quest has led to being able to remove 4 pounds of weight from the original 10 pounds required in the beginning. A 40% reduction and I have yet to install ruby or sapphire jewel bearings, or pallets.