DUPLEX 18Kt Yellow Gold Pocket Watch With Original Key 1850
You are bidding on an 18 Kt yellow gold open faced key wind pocket watch, made in France in 1850. The pocket watch comes with original key.
Dial: The later white enamel dial has black Roman numerals and outer minute divisions. The dial has nice hands and is protected by a glass in great condition.
Movement: The duplex escapement movement with compensated balance and frosted gilt bar movement is in working condition; however we cannot guarantee accuracy for an antique pocket watch.
Case: This pocket watch is lying in an 18 Kt yellow gold case. The back of the case is a beautifully engraved decorated monogram. The cuvette is signed: "Delaunay frères a Paris" and numbered N216.
See Tardy Book, page 170, Delaunay frères a Paris.
Signed: DELAUNAY - Diameter 46mm - Circa 1850
DUPLEX ESCAPEMENTS: The duplex escapement originated in France circa 1724, and was invented by J.B. Dutertre. The duplex escapements were popular as well among the English makers of good watches from the late 18th to about the mid 19th c, until supplanted by the Detent and Lever escapements. Pierre Leroy is said to have invented it c1750 and in 1782 a patent was granted in London to Thomas Tyrer. It continued to be used in some machine-made American pocket watches. The escape wheel has two sets of teeth at right angle, on for locking and for impulse which is given in one direction only to an impulse pallet on the balance staff. Some continental versions have rest escapement.
The duplex escapement has a slot in the roller on the lower part of the balance staff on the right, that allows a pointed tooth of the escape wheel to rotate to the next position, where it is held up. This causes an upright tooth on the escape wheel to impulse the balance staff.