Movement record · Switzerland

Jaeger-LeCoultre Calibre 101

Partially verified

Extremely small rectangular manual calibre

Technical specifications

Diameter: Very small rectangular form; dimensions quoted vary by source
Height: Not recorded in the sources consulted
Jewels: Varies by generation
Frequency: 21,600 vph (3 Hz) in later generations
Power reserve: Approx. 30 hours
Winding: Manual, stem wind
Setting: Pendant set
Escapement: Swiss lever
Balance: Very small balance
Complications: Hours and minutes only

Identification features

Exceptionally small rectangular movement, normally identified by documentation rather than by sight

Known variants

Successive generations with revised construction

Servicing notes

Cleaning, lubrication, mainspring and pivot work belong with a qualified watchmaker working from calibre-specific documentation. Conserve original parts: replacing a worn component with a modern substitute changes the object, and refinishing plates or dials destroys evidence.

General guidance only. Antique movements should be serviced by a qualified watchmaker.

Historical significance

Among the smallest mechanical watch movements ever put into series production, and a demonstration of the limits of miniaturisation.

Diagram

Schematic: plate and bridge layout. An outline schematic drawn to show the arrangement of the parts discussed here. It is not a dimensioned working drawing and does not depict a particular maker's calibre.

Sources & references

de Carle, D., Watch and Clock Encyclopedia
Period trade material catalogues and calibre reference compilations (edition-dependent)
Published manufacturer technical documentation where available

Where sources disagree, the disagreement is stated rather than resolved silently.