Complication · Display
Up-and-Down Indicator
Partially verifiedAn early, chronometer-associated form of power reserve indication, showing the winding state of the mainspring as 'up' (fully wound) through 'down' (run down) on a graduated arc.
Definition
An early, chronometer-associated form of power reserve indication, showing the winding state of the mainspring as 'up' (fully wound) through 'down' (run down) on a graduated arc.
Historical origin
Associated principally with marine chronometers of the eighteenth and nineteenth centuries, where knowing the winding state was operationally important for maintaining reliable rate at sea; the same mechanism carried over into some high-grade pocket watches.
How it works
As with the modern power reserve indication, an up-and-down indicator takes its drive from the fixed number of turns the mainspring barrel makes between fully wound and fully unwound, geared down through a small train to a hand reading against a scale.
In chronometers this was frequently a dedicated subsidiary dial marked plainly 'up' and 'down' at its extremes, intended for quick operational reading by a ship's officer responsible for daily winding.
The mechanism and the modern 'power reserve indication' are functionally the same device; the terminology 'up-and-down' is largely historical and associated with marine and pocket chronometers rather than modern wristwatches.
Pocket watch context
Found in high-grade pocket chronometers and some marine deck watches, where daily winding discipline made a clear winding-state indicator operationally valuable.
Wristwatch context
Now essentially synonymous with the modern power reserve indication; the 'up-and-down' name survives mainly in historical and chronometer contexts.
Identification
- Subsidiary dial explicitly marked 'up' and 'down' rather than in hours
- Most often found on marine chronometers and precision deck or pocket watches
Servicing notes
As for power reserve indications generally, the driving gear train must be correctly calibrated to the barrel; specialist service is required for accurate readings.
General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.
Diagram
Sources & references
- de Carle, D., Watch and Clock Encyclopedia
- Specific dating of the earliest up-and-down chronometer indicators was not independently verified.
Where sources disagree, the disagreement is stated rather than resolved silently.