This word, remontoir, stamped on the cuvette of a Swiss watch, often constitutes a bitter disappointment to collectors who believe they have found a watch fitted with the sophisticated item described in the next entry.  In fact, it is merely French for stem-winding.

Remontoire is an arrangement, invented by John Harrison and found only in chronometers and first-class watches, for preventing the declining power of the mainspring as it unwinds from creating a loss of pace at the balance.   (The fusee cannot do this precisely enough.)   The remontoire consists of a small slave drive-spring, wound automatically at very short intervals (perhaps only a few seconds) by the power of the mainspring;  it is this slave spring which powers the escapement, the mainspring having no influence on this part of the train.   Thus the watch ‘runs down’ and is automatically re-wound hundreds of times a day – often enough for the momentum of the balance to carry it over the tiny loss of power, which in any event is averaged out over the watch's daily rate.