The Reason
The Subscription (Souscription) pocket watch is a relatively simple timepiece, with a single hand and enamel dial. Launched through a publicity brochure in the late 18th century, it was marketed on a subscription basis, with a down-payment of a quarter of the price with each order. Approximately 700 examples were made (the majority between 1798 and 1805), with either gold or silver cases with various technical variations. It has a cylinder escapement made with ruby.
(Launched in 1797)
The watch at the time of manufacture cost £600.- one quarter was payable on order/subscribing, the balance was paid when the watch was completed. A guarantee was given that there would be no delay in delivery and that they would be delivered in the order they were commissioned.
The concept behind the watch was to make a more simple and affordable time piece than A.-L. Breguet had been known for, to be able to attract a larger clientele.
The first general statement at the release of the watch noted that the watches were intended for “for Astronomy and the Navy”. They were designed with the object to be used on a daily basis and provide accurate and reliable service.
The watches are large in diameter, the movements measuring 61mm in diameter. They provided a power reserve of 36 hours, temperature compensation for the carbon steel balance spring, shock protection for the balance pivots and a ruby cylinder escapement.
The large dial with 5 minute divisions is partly linked to the reason for the size of the watch. A.-L. Breguet suggested that despite having a single hand the watch would still permit the user to read the time to the closest minute as the hand passed through the 5 minute increments.
The movement held a large central barrel which could be wound from the front or back of the watch. The barrel also held the single hand, when the watch was set to time (in one direction) from the dial side the watch would be wound at the same time. Then once set to time, the barrel mainspring would be wound from the case back side. The hand itself was made in such a way that it could be directly physically moved by the user of the watch, once the front bezel was open.
The dial was made from enamel and was marked with the Breguet secret signature, which was machined into the dial by use of an early form of pantograph. This was done as a result of the copies that were being made by other manufacturers at the time producing fakes of Breguet watches. Marking enamel in this way was a complex process and difficult to reproduce cleanly.
Both the bezel and case back were hinged and could easily be opened and closed by the owner with out the need of a case knife. Part of the robust nature of the watch comes from the pure scale of the design. The engine turning on the sides and case back have multiple roles, aesthetic, grip and avoids finger prints.
The dial is locked in place by a single, blued steel screw below the 12, an element which became familiar with many Breguet timepieces. The case secured the concentric location of the dial on the movement. The large diameter and slightly domed shape was enamelled on both sides to assure the tensions with in it were even. In the last of the images directly below the hand has been removed to be able to dismantle the dial.
The blued steel hand with cerated tube, allowing for it to hold tightly but still be turned manually if needed.
The two images below show different views of the balance assembly with the balance cock, parachute system for protecting the upper balance pivot and the index for regulating the watch.
In addition to providing the function of time keeper the watch was an aesthetic object designed to be purchased (as is often the way today) on the basis of its craftsmanship and beauty. The bridges were also crafted in a way that were aesthetically following a specific design code. Those for the 3rd and 4th wheels, (the 4th shown below) were filed to create the effect of a fold in the material on the vertical section.
The dial removed showing the simplicity of construction and revealing the steel escape-wheel and cylinder. The barrel had a double ‘stop-work’ fitted into the barrel cap below the bridge upon which the hand was pushed on to. The stop-work allowed the watch to be wound a set number of turns and not to wind down completely, assuring that only the central force of the mainspring could be used to enhance time keeping. The majority of watches made though-out history would only have a single stop-work fitted. The reference stamped on the main-plate “1836” is also found on the inner case back and marked under the balance cock.
The case with the movement removed. The movement is located in the case with a small pin that assure it can not turn and then three large blued screws lock it in place.
The large eccentric screw below the balance is one of the three that holds the movement in place. The hand engraving with the flamboyant curves is typical of Breguet’s style and became part of the companies DNA from its very beginning.
The view of the escape wheel and the ruby cylinder normally hidden under the dial.
Views of the movement removed from the case.
In 2005 Breguet watch company introduced a new collection called Tradition, the basic design cues derived from this movement as well as the philosophy behind it. The form of the bridges, symmetry of construction, and highly visible mechanics and with the Breguet 7097 the centrally positioned barrel.
The balance assembly removed. The large brass screw-like piece set into the main-plate is for adjusting the position of the cylinder in relation to the escape-wheel.
The balance cock sits on a plate (shown below) which carries a small steel piece which the lower balance pivot, turns in, this assembly is then adjusted by the above mentioned brass screw. The small hole in the brass screw acts on a pin which protrudes out of the balance cock base, both acting as a steady pin and a means to adjust penetration of the cylinder and escape wheel.
Cylinder escapements are frictional rest, there is a constant friction placed upon the balance. The majority that were made historically were steel on steel and the pivot was placed on top of the cylinder. The result was poor time keeping as a result of excessive friction and they would ware with use. In this execution the cylinder is made from ruby, and the pivot sits on the inside of the cylinder. This made the construction more solid and reduced friction. In addition to the machining of the vertical cylinder walls the edges upon which impulse is given to the balance are rounded. In addition the escape-wheels were made with a strength of construction that was never used by any other company then or afterwards. To reproduce these cylinders today would be a complicated process, producing them two hundred years ago was technological extraordinary.
Below, the original parachute shock protection system for the upper balance pivot. The pivot would oscillate within the jewelled setting. The blued screw holds in place a plate which houses the end jewel which limits the end shake of the balance staff.
The index with bi-metallic adjustment. The index adjusts the effective length of the balance spring, the longer the spring the slower the watch runs, the shorter the balance spring, the faster it will gain time. The last coil of the balance spring would pass through a section between a brass pin and a block at the end of the bi-metallic strip set into the index. The reason for this addition was to compensate for the effects of temperature on the balance spring which was made from carbon steel. As the temperature of the movement would increase, due to climate, location etc, the spring would become weaker and the watch would run slower. As the temperature dropped the spring would become stronger and the watch would gain. The bi-metallic adjustment would increase or reduce the distance the spring could move, between the pin and the end block of the bi-metallic piece, acting as compensation for the variable time keeping resulting from the temperature.
The balance removed from the balance cock. The pin protruding from the rim of the balance prevents the balance from oscillating too far, due to a shock, and locking on the other side of the cylinder.
The hardened steel escape wheel. All functional surfaces were mirror finished. From the ware found in parts of the gear train the watch has been used considerably during its life, however there are no signs of ware on the surfaces of the cylinder or the reciprocating escape-wheel teeth. Implying the ruby cylinder and escape-wheel teeth were both extremely hard and perfectly finished.
In the centre of the image is the small steel piece that the bottom balance pivot rotates in.
The bridge/cock removed from the second wheel.
The overall finish of the pinion below remains sharp, mirror finished and unworn. This is comparable with any finishing executed today and an improvement on many contemporary mass produced pinions.
The 2nd wheel removed, leaving the barrel, 3rd, 4th and escape wheel.
The final train bridges.
2nd, 3rd and 4th wheels.
All of the wheels removed, the barrel remaining.
The barrel is held sandwiched between its bridge, the ratchet wheel and the plate (removed) shown below.
The long rectangular steel click acts upon the ratchet wheel. The ratchet wheel hooks in one direction on the inside of the click. The force of the mainspring is considerable, the ratchet wheel being held inside of the click is an additional security reducing the likelihood that over long periods of time the force of the mainspring on the click would cause it to flex and move vertically.
The barrel assembly removed from the movement.
The remaining main-plate.
Summary
The Souscription pocket watch was built over 200 years ago. In addition to the originality of its design and technical innovation, is the thought process and entrepreneurial aspect linked to this watch. Even its name is a result of a commercial concept to facilitate the purchase of such a timepiece, and expand the companies client base.
A single handed watch easily showing the time, combined with the early execution of shock protection, a ruby cylinder, the multiple sandwiching of the ratchet wheel/ barrel arbour, the simple but original click system and the bi-metallic temperature compensation. A system to combat counterfeiting through a difficult to reproduce secret signature. Results in an extraordinary and horologically important timepiece.
After two centuries, it continues to function perfectly.
Watchmaking remains a combination of function, innovation, art and being entrepreneurial. What it was in 1800 is clearly shown by A.-L. Breguet, and how it resonates with today’s world stands to show that regardless of the passage of time, and the change of technologies somethings in watchmaking remain the same.
To learn more about Breguet www.breguet.com