Swiss Chronometre Question

[Tom McIntyre]

I think you are describing what is called a pivoted detent chronometer escapement.

In operation, the escape wheel rests on the locking stone of the detent. When the balance passes in one direction, a small gold spring is bent out of the way to let the balance pass and nothing else happens. When the balance passes in the other direction, the gold spring presses against the pivoted arm and the arm moves to release the escape wheel. The escape wheel accelerates rapidly and gives impulse to the balance to keep it oscillating.

When the watch is operating correctly it is difficult to see the action of the escape wheel since it moves so fast from lock to lock.

The hairspring around the pivot of the detent makes it move back into position after releasing the escape wheel tooth so it can catch the next tooth.

Tom McIntyre
2nd VP Elect
Tommy the JOAT's Web (http://www.AWCo.org)

[Tom McIntyre]

You may be able to find marking under the dial of the watch. Many Swiss makers made these and the bulk of the manufactured parts were produced by many small shops for many assemblers and adjusters.

Pocket chronometers are more collictable than lever watches all other things being equal in terms of condition and appearance.

This is a pivoted detent Swiss watch by H. L. Matile that was cased and converted to stem winding by Charles DeLong.

http://www.awco.org/MWCo/DelongSwiss/movement_small.jpg (http://www.awco.org/MWCo/DelongSwiss/movement.jpg)

Tom McIntyre
2nd VP Elect
Tommy the JOAT's Web (http://www.AWCo.org)

[Dr. Jon]

Sounds like a neat movement, especially if it runs well.

These were made before major Swiss brands emerged. There were lots of retailers who drew on a well developed infrastructure. With teh helical spring it is a far above average piece and was probably made to order. Many such buyers would NOT want the retailers name on the piece. OFten the cuvette was the only place it would have been signed and with that gone, attribution os tough.

A scan woudl help. IF it is Geneva bar movement it prtobably came from that area. I have a Matile which like Tom's is a Locle style movement.

YOU can use the style and jeweling to gat an idea of the date. With a S/N in the 8000 range it had to be a fairly well established dealer who was in business for a while. Look in such books as Shenton's Pocket watches 19th and 20century watches for similar styles and S/N's. You may find a match.

Dr. Jon