HOME PAGE  ::  THE WATCH CABINET  ::  GLOSSARY  ::  ESCAPEMENTS  ::   ENGLISH WATCH REPAIR   :;   HALLMARKS   ::  LINKS



ENGLISH DUPLEX WATCH
Morris Tobias & Co., Liverpool, 1804

Image of duplex1.jpg

Pair-case watch by Morris Tobias & Co., Liverpool.   Gilt brass movement with duplex escapement, elaborate pierced and engraved cock embodying Masonic symbols, capped ruby jewels on the escape-wheel and large regularly cut diamond endstone;  signed Morris Tobias & Co Liverpool & LONDON No. 2745. Gilt brass dust-cover, signed as movement.   White enamel dial with roman chapter-ring and large subsidiary seconds dial;  gold hands.   Brass outer case with traces of gilding;  silver-gilt inner case, also showing considerable wear to the gilding, hallmarked London 1804, with maker's mark W.M beneath asterisk.   Lunette glass (somewhat dulled and scratched).   Case diameter 57mm.

The house of Tobias is best known for its rack-lever watches of the 1820s, but here we find them already leading the way in technical innovation twenty years earlier.   This is a watch for the Industrial Revolution;  every detail – its sheer size, the florid engraving of the signatures, the oversized endstone, the assertive new technology of the duplex escapement and the new-fangled seconds dial – expresses the pride and self-satisfaction of a rising commercial class.

Image of duplex_dial.jpg
Image of duplex_movt2.jpg

The dial already shows all the characteristics of the typical 19th-century English watch;  it is flat rather than convex, the enamel has a matt finish, the chapter-ring is tall and bold, and there is a subsidiary seconds dial marked in tens.   It could easily have been painted forty years later.
The movement likewise looks forward, with early examples of the Bosley regulator and the separate bridge (held by two screws and bearing the engraved signature) over the spring-barrel.   Only the full-width pierced cock shows that this is not a mid-century movement.

Image of duplex_balance.jpg
L E F T
This view of the balance shows why the duplex escapement never became popular – and why this watch does not run*.   The pink object at centre is the locking-roller, a tiny sleeve of ruby fitted over the balance-staff and with a slot cut in it to engage with the long teeth of the escape-wheel.   This roller, struck 216,000 times a day by the sharp brass teeth, tended to wear away;   in this example half of it has broken clean off.   Just beyond it on the balance-staff is the comma-shaped impulse cam which engaged with the short set of teeth;  on later examples this would have been jewelled.   Note the seven turns of the hairspring;  the equivalent on a verge watch would have had only three.

B E L O W
This watch-paper, dated 1859 on the back, shows that the watch was in America quite early in its history (it may even have been exported there when new;  Liverpool was the chief port of embarkation for the Atlantic crossing, and the early Americans seem to have favoured base-metal cases).   Just after buying the watch I received an appeal from the watchmaker's great-grand-nephew which I could not resist, and so the paper is now back in the U.S.A.

* Since writing this I have experimented with re-profiling the roller with a “prosthesis” made from a blob of Superglue, filed and whittled to shape.   This actually worked — not permanently (it lasted nearly three months before the sharp escape-wheel teeth chipped the glue away) but most gratifyingly nonetheless, considering that the watch had probably been silent for a hundred years or more.


B E L O W
Dust-caps were not common at this early date.   Usually the raised panel over the cock-table was cut away to fit the table itself;  here, however, Tobias has preferred to use the space for some more gloriously florid advertising.

Image of duplex_cap_2.jpg 		Image of duplex_paper_1.jpg


Click here for the sound of the Duplex watch

The tick is similar to that of the Barnard verge, but louder, partly because the balance is swinging more strongly and partly because the much larger case has an amplifying effect.   The alternation of strong and weak beats stems from a different cause, however:  in the duplex, impulse is given only on clockwise swings, and on the return of the balance one hears only the much lighter contact between locking-roller and long teeth.