RESTAURATION
La pendule à oiseau chantant de Pierre Jaquet-Droz
LIEU
Musée d'horlogerie du Locle,
Rte des Monts 65, 2400 Le Locle

ON LE LOCLE:
singing bird pendulum clock by PIERRE JAQUET-DROZ 

Chaînes à cinq maillons de type Jaquet-Droz et barillet
Oiseau et jeu de flûtes
Détails des bronzes
Détails du style retour d'Egypte

Artifact:

A large-scale imposing and majestic pendulum clock in the Empire Egyptian Revival style. The mahogany cabinet is adorned with perfectly carved decorative elements from the Napoleonic Empire, in gold-plated bronze. Displaying a very high level of workmanship, the elements represent sphinxes, winged victories, busts with Egyptian hairstyles, swans and lotus leaves. There are two hands, both in the oriental style. The movement, powered by a double fusée and chains, sounds the hours and quarter hours on two bells.

The escapement has a crown-wheel. The brass plate bears the signature "Pierre Jaquet-Droz à La Chaux-de-Fonds".

The bird's song is produced by a serinette with a pin barrel, housed in the upper section of the clock. This instrument can play six different airs on ten flutes. During the melody, the bird pivots on the spot, opening its beak, shaking its tail feathers and puffing up its chest. The motor mechanism for the serinette is located underneath the clock movement.

These two mechanisms are connected by a small belt. The serinette can be made to start playing manually, as desired, by pulling the small cord located on the left of the clock or activated automatically to sound every hour. A small lever, placed on the right hand side of the cabinet, is used to select one of the six available airs. A second lever, underneath the first, is used to activate the serinette or to silence it, for example during the night.  

  • Dimensions: height 92.5 cm, width 43.3 cm, depth 27 cm
  • Materials: wood, bronze, brass, feathers and enamel

Aim of the restoration project:

The aim of the restoration of the Jaquet-Droz pendulum clock is to return it to a condition similar to its original state, thereby preserving the special features of this piece (the five-link chains, for example). It is a significant item, and the pride of the MHL collection.
The clock has not been operated for a number of years, so it is therefore crucial that each component is removed and cleaned. The mechanisms require a complete service.
The cabinet needs to be retouched. The bronzes must be removed so that the cabinet can be entrusted to a cabinet-maker. The scale of the damage will be determined using ultra-violet light to see whether it is necessary to sand and refinish the French polish.
The bronzes must be cleaned gently in a bath to ensure the gold plating is not removed. Some of the bronzes must be re-gilded with mercury; these may have previously been cleaned with aggressive products and have lost their original gilding.

Reconstruction of the Jaquet-Droz chains:

The chains of the motors driving the clock and the serinette require reconditioning. A swage for manufacturing these chains must be created, as they are unlike other chains (5 links). We could either use the swage (kept by MHL) created by CIFOM for the restoration of the Jaquet-Droz clock inventory no. 1535 as the basis. Or, as work was carried out on chains by MIH for the Breguet clocks, we could also use this procedure as the basis. Whichever method is chosen, this immense project will require considerable time and should eventually enable MHL, MIH and MAHN to have the resources to recreate chains of this type. It is conceivable that this work will be entrusted to a paid intern whom we would train. A test will be carried out to estimate the working hours required for creation of a swage. It must be noted that the Jaquet-Droz clock alone has four chains, each approximately 3.5 metres.

Intervention on the mechanisms:

  • Disassembly, recording and taking of photographs
  • Complete cleaning of the mechanisms
  • - Reassembly                                                           
  • Study of the serinette movement                            
  • Report on the work                                              
  • Study of the chains                                                 

Approximately 455 hours

Other interventions:

  • Study of the cabinet
  • Study of the cabinet bronzes
  • Cleaning of the bird

Approximately 100 hours

Intervention by an art restorer:

  • Restoration of the cabinet
  • Restoration of the serinette (bellows, pins, set of flutes) and the bird