VR-288 - Precision Regulator with Riefler pendulum and jeweled pallets of 1 month duration
Siegmund Riefler was born 9 August, 1847 and died at age 65 in Munich in 1912. The clocks using his patented pendulum designs are recognized as some of the best mechanical time-keepers ever made. To quote an early author - Riefler invented a compensating pendulum whose insensitivity to temperature changes is little short of fantastic. In the days before the Quartz crystal changed the fundamental definition of accuracy, Riefler precision pendulum clocks were placed in observatories on all five continents as well as in scientific institutes where accurate time was very important.
This clocks pendulum is marked Riefler, München, D.R.P 100870, and 1134. The rod is made of Invar, a nickel-steel alloy (35.7% Ni, 64.3 % steel) invented by Dr. Charles Guillaume towards the end of the 1800's. Invar has a very low temperature coefficient of expansion, making it an ideal material for the construction of pendulum rods. There is a short aluminum tube that fits up inside the pendulum bob which provides temperature compensation, and a very heavy bob - the rod/bob weighing nearly 16 pounds.
As discussed elsewhere in this catalog/website, Precision Regulators are the epitome of mechanical timekeepers. Every thing about them is built to last, and to be extremely reliable - achieving the target accuracy of a minute a month.
The case, with beveled glass to all nine windows, is exceptionally well made, as was the norm for the Jugendstil-style cases. By the latter part of the nineteenth century the use of Veneer was significantly reduced, giving us cases that are, like this one, made of solid wood. The case is beautifully finished inside and out and in excellent condition: Even the wooden strips holding in the glass are finished.
It is interesting to note that there were never wall stabilizers in this case, or even holes to mount it to the wall. Additional points that I believe are worth noting about this clock include:
-The weight is offset to one side of the case to minimize its impact on the swing of the pendulum as the weight drops.
-The jeweled pallets - minimizing wear and friction - Jeweled pallets are a fundamental requirement for being considered a precision regulator.
- All of the parts are beautifully plated and in very nice condition. Note though that there is some rubbing and tarnishing to the front of the bob.
-When you look at the back of the mechanism note the use of inset (mounted with two screws each) hardened brass bushings for all of the pivots.
-When you look at the picture of the crutch note that the crutch only impulses the pendulum rod to one side, thereby reducing the impact of the mechanism on the swinging of the rod, a feature that contributes to making the clock a very precise instrument.
-The suspension spring upper pivot is held precisely in place by two thumb screws to the end of the upper pin
-The massive mechanism mount - with arms that support the mechanism being a full 1 inch square where they attach to the backing plate.
-The 4 mm (1/6 inch) thick plates
-Maintaining Power to keep the clock running in the forward direction while winding.
Note too the 5-spoke pulley with engraved cover plates - matching the engraving on the weight, the old glass throughout, and the small weight shelf on the pendulum rod for the most precise rate adjustments: Everything about this clock bespeaks quality and precision.
Read MoreThis clocks pendulum is marked Riefler, München, D.R.P 100870, and 1134. The rod is made of Invar, a nickel-steel alloy (35.7% Ni, 64.3 % steel) invented by Dr. Charles Guillaume towards the end of the 1800's. Invar has a very low temperature coefficient of expansion, making it an ideal material for the construction of pendulum rods. There is a short aluminum tube that fits up inside the pendulum bob which provides temperature compensation, and a very heavy bob - the rod/bob weighing nearly 16 pounds.
As discussed elsewhere in this catalog/website, Precision Regulators are the epitome of mechanical timekeepers. Every thing about them is built to last, and to be extremely reliable - achieving the target accuracy of a minute a month.
The case, with beveled glass to all nine windows, is exceptionally well made, as was the norm for the Jugendstil-style cases. By the latter part of the nineteenth century the use of Veneer was significantly reduced, giving us cases that are, like this one, made of solid wood. The case is beautifully finished inside and out and in excellent condition: Even the wooden strips holding in the glass are finished.
It is interesting to note that there were never wall stabilizers in this case, or even holes to mount it to the wall. Additional points that I believe are worth noting about this clock include:
-The weight is offset to one side of the case to minimize its impact on the swing of the pendulum as the weight drops.
-The jeweled pallets - minimizing wear and friction - Jeweled pallets are a fundamental requirement for being considered a precision regulator.
- All of the parts are beautifully plated and in very nice condition. Note though that there is some rubbing and tarnishing to the front of the bob.
-When you look at the back of the mechanism note the use of inset (mounted with two screws each) hardened brass bushings for all of the pivots.
-When you look at the picture of the crutch note that the crutch only impulses the pendulum rod to one side, thereby reducing the impact of the mechanism on the swinging of the rod, a feature that contributes to making the clock a very precise instrument.
-The suspension spring upper pivot is held precisely in place by two thumb screws to the end of the upper pin
-The massive mechanism mount - with arms that support the mechanism being a full 1 inch square where they attach to the backing plate.
-The 4 mm (1/6 inch) thick plates
-Maintaining Power to keep the clock running in the forward direction while winding.
Note too the 5-spoke pulley with engraved cover plates - matching the engraving on the weight, the old glass throughout, and the small weight shelf on the pendulum rod for the most precise rate adjustments: Everything about this clock bespeaks quality and precision.
