- Museum number
Alarm mechanism/timer prototype; two hand-written dials, inner marked 0-60 and the outer 0-12; mechanism based on Ingersoll thirty-hour movement with pin-pallet lever escapement.
Height: 20 millimetres
Height: 50 millimetres
Length: 70 millimetres (box)
Length: 50 millimetres (timer)
Width: 60 millimetres
Width: 73 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Ingersoll
Prototype 12 hour timer based on an Ingersoll calibre watch with a pin pallet lever escapement.
Case: No case, the whole is mounted on a steel plate of rectangular shape with an arch top. Three nuts secure the movement to this plate.
Dial & Hands: The hour and minute hands have been replaced by two discs inexpertly painted with, on the minute arbor 5 second marks and the numbers 0,10,20,30,40,50, and on the hour disc the half hours marked and the numbers 0,1,2,3,4,5,6,7,8,9,10,11. Also mounted on the cannon pinion is a cam shaped disc with also o post set into it. Another cam is mounted on the hour pipe with a cut out the depth of the lower part of the minute cam. When the cut out and the low part of the minute cam coincide a lever pivoted beneath the movement can fall and release a catch. This catch is arranged to move aside with safety if the watch movement is set backwards.
Movement: This is a type 5D movement with the keyless work removed, the pillar screws replaced by threaded nuts and hand set and winding pieces fitted.
Ebauche Marks: none.
Winding System: Keywound and button hand set.
Dimensions: The steel plate is 49.5 mm. wide and 57.7 mm. in height. The overall depth is 20.4 mm.
Provenance: Donated by the Heron Corporation Ltd in 1983.
- Not on display
- Latest: 3 (Jun 2018) in pieces
- Acquisition date
- Britain, Europe and Prehistory
- Registration number