Quarter Repeater with Breguet Caliber and Ruby Cylinder Escapement

Quarter repeater mechanism with MF (MH) stamp, number 350. Paris, France, circa 1820.

Until recently, this mechanism was in the collection of the famous collector Paul Chamberlain and is mentioned as number 701 in his book ‘It’s About Time’, published in 1943. After a tough battle at the auction, the watch has now migrated to my collection.

Firstly, the mechanism is an interesting model for studying the higher art of watchmaking in the early 19th century.

The main features of the mechanism:

  • Ruby cylinder escapement
  • Quarter repeater
  • Shockproof ‘parachute’ device
  • Thermocompensation device
  • Condition is close to perfect

Classic Quarter Repeater with Breguet Caliber

Repeater – A device for audio indication of time in hours. Repeaters were relevant before the popularisation of electricity. When you have a repeater in your pocket while in a dark room or on an unlit street, you can find out the time without lighting a lamp or a candle. One only needs to press the button, and the watch will strike the current time. Low-pitched chimes correspond to the number of hours, while high-pitched chimes correspond to the number of full quarters. The sound of the repeater can be heard here.

By all indications, mechanism No. 350 dates back to the lifetime of A.L. Breguet. It was made in Paris, probably on the same street and by the same craftsmen who also had contracted work at the Breguet workshop. A. L. Breguet himself often used both very similar and completely identical mechanisms in his own watches. For comparison, below on the left is photo of a pocket watch from the catalogue ‘Breguet in the Hermitage’ (St. Petersburg, 2004).

Left: Breguet watch from the State Hermitage collection (for more pictures see pages 92 and 93 of the catalogue). Right: Mechanism 350.

The proportions, the shape of the bridges, the arrangement of the wheels, and the number of teeth are all the same. The differences are the small details that the watchmaker would change each time as he pleased.

The Breguet Caliber – the Characteristic Shape of the Bridges

The location of the bridges is a characteristic feature of the Breguet watch design. According to the manufacturing guidelines, each bridge must hold the minimum number of axles on the board in order to make the watch more convenient to service. This type of caliber was first proposed by Jean-Antoine Lepine, but in his repeaters the bridges were not as well fitting as in ordinary watches. In the 1790’s, Breguet perfected this design, reducing the thickness of the repeater part and thus making it more reliable.

Pay attention to the balance axis. The first ever shock-proofing device, the legendary ‘parachute’ of Abraham-Louis Breguet, is located underneath the bridge.

In the 200 years that have passed since A.L. Breguet’s development of the repeater bridges, the basic scheme of the repeaters has remained relatively unchanged.

The Mechanism Under the Dial

The entire quarter repeater system is located here.

Pay attention to the polish and finishing of the steel parts – one could not do better even now in the 21st century. Everything is polished to a mirror shine; chamfered, corners rounded, and chiselled springs of complex shapes. The screws are in the same style, and the steel gunmetal polished to a mirror-shine. In his watches Breguet often used modified combs of different shapes, but of the same level of quality.

The Pare-Chute Shock-Proofing Device

One of the more widely known inventions of A.L. Breguet is the Pare-chute, or ‘parachute’ device, the first device in the world that was designed to protect the thinnest part of the watch – the pivots of the balance wheel – from breaking upon impact.

The essence of the ‘parachute’ design is the in the spring-loaded fastening on which the cone-shaped pivots, held in place by small cone-shaped dishes, are mounted. In case of impact, this will remove the load on the pivots, which is most cases will protect them from damage.

A metal thermocompensation bracket extends away from the stroke regulator. When the temperature changes, it expands and subtly adjusts the length of the spiral, compensating for the resulting difference in stroke.

Another small but significant detail is how the trigger is finished to the right of the balance axis. The chamfers are perfectly shaped. And it’s all done by hand!

The ‘parachute’ close up. Pay attention to the dimensions, the perfection of the circles. If you look carefully at the jewel, a drop of oil and the tip of the balance axis is visible.

This shock-proofing design is still used to this day in several different modified forms.

The Ruby Cylinder

The narrowest part of this movement, and the most amazing, is the balance wheel, made the finest natural Ruby. The cylinder escapement is characterised by consistent wheel-to-axle contact, which quickly wears out the steel cylinder. Thus, replacing the cylinder head with a Ruby is an expensive but reliable way to combat wear.

The balance wheel at maximum zoom. The transparent part of the wheel is a natural polished Ruby of cylindrical shape. Judge the degree of increase by the size of the spiral at the bottom. The diameter of the Ruby cylinder is only 1.2 millimetres!

It is incredible that this design was made 180 years ago, by the hands of long-gone masters.

I would like to express my gratitude to Andrey Babanin for his help with the macro photography.