- Museum number
Showroom model of pocket watch.
Skeletonised movement; gear train, terminating with pin-pallet lever escapement, driven by electric motor housed in wooden base via a chain and sprocket on the fourth wheel arbor.
Dial of perspex with minute circle and Arabic hour numerals backed by disc of white card; subsidiary seconds.
Black painted metal hands.
Case cut away to leave only a small section near the pendant.
- Production date
Height: 62 centimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Ingersoll
Great Britain, c. 1955
Showroom model with a pin pallet lever escapement.
Signature: On the dial on a black cartouche in gold is 'INGERSOLL' Around the seconds hole, set out in circular fashion is 'MADE IN GT. BRITAIN'
Case: No case, but there is a short section of case band that supports the pendant and the button and stem, all of this is chrome plated.
The watch stands on an oval base which contains the electric motor that drives the model. On the back of the base is the switch and running from the base is the cable which has a plug for the feed from the mains. On top of the base is an oval chrome plated disc to which is secured two chrome plated pillars which support the movement. These pillars are connected to two of the movement pillars.
Dial & Hands: A dial of Perspex with back painted with black Arabic numerals and minute circle. A subsidiary seconds circle. Black painted metal hands of spade design and a black seconds hand. The dial fixed to three pillars on the front plate by chrome plated screws.
Ebauche Marks. None.
Frame: A brass frame with both back and front plates separated by four pillars. The plates are skeltonised so as to reveal the interior parts.
Barrel and Mainspring: No mainspring, the train is driven by the electric motor in the base via a chain. The chain runs on a pulley mounted on the forth pinion arbor and on which it can slip. This slipping gives the same effect as a clutch the drive being arranged to be faster than required.
However a dummy barrel is provided so that the winding can be demonstrated and to show a full compliment of parts.
Train: The brass train wheels with five crossings. The escape wheel with four.
Escapement: A straight line layout pin pallet lever escapement with long lever, effectively a double roller with a round steel impulse pin. The steel pallet pins are set in a brass lever. An equidistant locking escapement.
No. of teeth embraced 3½.
Balance & Spring: a monometallic brass balance with a plain rim. Balance diameter 112 mm., thickness 2.3 mm. A steel flat spiral spring with approx 8 turns.
Means of Regulation: An index on the back plate, no divided scale or indication as to which direction to move the index for fast or slow.
Train Counts and Beat Rate:
Great wheel (Barrel) 60
Centre wheel 60 pinion 7 Rotates once an hour
Third wheel 45 pinion 10 Rotates once in 10 minutes
Fourth wheel 45 pinion 9 Rotates once in two minutes
Escape wheel 15 pinion 9 Rotates once in 24 seconds
84.375 beats a minute
Motion work: cannon pinion 8
minute wheel 24, minute pinion 7
hour wheel 28
Keyless work: Positive set keyless work of the type connected with Ingersoll type 5 movements.
Dimensions: Base width 380 mm., depth 134 mm., height 125 mm.
62 mm. deep on the top of the base.
Movement: Diameter 340 mm., height 90 mm.
Provenance: Donated in 1983 by The Heron Corporation Ltd.
- Not on display
- Latest: 2 (Oct 2016)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number