Large & Rare Factory Slave Clock by Synchronome Electric · London
IG222100
A large, rare and historically significant industrial factory slave clock by the Synchronome Electric Company of London — one of the most celebrated names in British precision timekeeping, and a manufacturer whose output is far less commonly encountered than that of the volume factory clock producers. At an overall diameter of 24 inches, this is a commanding object; the dial alone spans 18 inches across.
Synchronome
The Synchronome Electric Company was founded in London in 1895 by Frank Hope-Jones, a figure central to the development of precision electrical timekeeping in Britain. Where other manufacturers produced clock systems for the institutional mass market, Synchronome built instruments of genuine technical distinction — their free-pendulum master clocks are among the most accurate mechanical timekeepers ever made, and their slave clock systems, driven by precisely timed electrical impulses from those master movements, set the standard for precision time distribution in British industry, science and public life throughout the early and mid twentieth century. A Synchronome on the wall of a factory, laboratory or institution was a mark of quality that went beyond the utilitarian — a statement that accurate time mattered to the people working there.
The Clock
The case is a substantial cast iron double-ring bezel construction — a stepped profile quite distinct from the single drum format used by most factory clock producers, the outer ring and inner bezel casting a deep shadow against the dial face that gives the piece an architectural quality in person. The finish is the characteristic institutional green, original and largely intact with the honest surface variation of a long working life. A single cast hanging bracket sits at the twelve o’clock position, original to the case, with a central fixing hole — this clock was hung from a single point, the format used where a ceiling bracket or wall plate carried the weight. Fixing holes are present around the outer perimeter of the bezel.
The dial is cream painted metal, carrying a face of bold Roman numerals in the classic Synchronome serif format — tall, clean, authoritative type of the kind that reads from across a large working floor. The inner minute track runs in a fine arrangement of alternating dash and tick markers around the perimeter. In the centre of the dial the SYNCHRONOME name is printed in a confident uppercase serif face, with LONDON below and the reference number 14 directly beneath the hand pivot — a production or batch number that adds a further layer of provenance to the piece.
The surface of the dial has developed a remarkable natural oxidation — large warm islands of amber and ochre lifted from the cream ground, with darker areas of original paint loss where the face has been exposed over decades. The result is a dial of extraordinary visual character: part map, part abstract painting, entirely unrepeatable. It is not damage — it is the record of the clock’s life, and it is one of the most compelling dial surfaces in this current run of pieces.
The hands are original and complete — a broad spade or tulip-form hour hand and a long tapered minute hand, both fitted with a small rounded counterbalance lobe at the tail, in blued or black steel. The hand form is quite different from the arrow style used by Gent, and immediately identifies this as a Synchronome product.
Power
As a slave clock, this piece is offered for display or conversion to independent battery or mains operation with a suitable replacement movement. Please enquire regarding conversion options.
Ideal For
- Serious collectors of British precision timekeeping instruments
- Large industrial conversions, loft apartments and double-height residential spaces
- Statement commercial, hospitality and cultural venue installations
- Architects and designers working with the finest of British industrial material culture
- Museum-quality display of electrical timekeeping history
Technical Specification
Maker
Synchronome Electric Company, London, England
Type
Factory slave clock · Cast iron
Origin
England
Era
Early to mid twentieth century, circa 1920s–1950s
Reference
Dial marked: SYNCHRONOME / LONDON / No. 14
Stock No.
IG222100
Dial Diameter
457mm (18")
Overall Diameter
610mm (24")
Depth
76mm (3")
Weight
6kg (please enquire to confirm)
Case
Cast iron stepped double-ring bezel · Original institutional green paint · Single cast hanging bracket at 12 o’clock · Perimeter fixing holes
Dial
Cream painted metal · Roman numerals · Original Synchronome London maker’s mark · Reference number 14 · Extraordinary natural oxidation surface
Hands
Original blued/black steel spade hour hand and tapered minute hand with rounded counterbalance lobe
Power
Offered for display or battery/mains conversion — please enquire
UK Export HS Code
9105 21 00
Condition
Very good condition for age and type. Cast iron case structurally sound with original green painted finish. Dial intact with extensive natural oxidation — a feature of considerable visual character. Original hands complete. Honest surface wear entirely consistent with extended institutional use.
Shipping
Worldwide shipping available — please enquire for a quote. All shipments are fully insured through Secursus.
