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The Encyclopedia of Horology

Clock · Torsion pendulum clock

Badische Uhrenfabrik anniversary clock

Partially verified

This table-top torsion pendulum clock, frequently referred to as an anniversary clock, was manufactured by the Badische Uhrenfabrik circa 1920. Constructed primarily of brass and glass, the piece features a round moulded brass base supporting two vertical columns that hold the movement. The upper portion of the frame is finished with pierced cresting. The clock incorporates a white enamel dial marked with black Arabic numerals and a minute track, accompanied by black hands. The timekeeping mechanism is key-wound and functions via a brass torsion pendulum comprising four balls suspended from a thin wire. The entire assembly is protected by a glass dome. According to the auction description, the clock is in a used condition commensurate with its age and is operational. The dial and movement both bear the mark "CB". It measures approximately 20 cm in diameter and 24 cm in height including the dome.

Front view of the Badische Uhrenfabrik torsion pendulum clock under its glass dome.
Front view of the Badische Uhrenfabrik torsion pendulum clock under its glass dome. — Invaluable. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.invaluable.com
Category
Clock · Torsion pendulum clock
Maker / attribution
Badische Uhrenfabrik
Reference
Not recorded
Catalogue / lot identifier
738
Source-reported date
circa 1920
Source-reported place
Germany

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Construction

The clock is designed as a table-top unit mounted on a round, moulded brass base. The visual presentation is defined by two vertical columns that serve as the structural support for the movement housing. A decorative element in the form of pierced cresting is positioned above the clock face, providing a frame for the upper portion of the assembly.

The time display is provided by a white enamel dial, which features black Arabic numerals indicating the hours, alongside a minute track. The dial is equipped with simple black hands. The entire assembly, including the pendulum mechanism, is enclosed within a protective glass dome, which serves to shield the internal components from external air movement.

Evidence for this section
  • “round moulded brass base, two columns supporting the movement with pierced cresting”
  • “white enamel dial with black Arabic numerals and minute track, black hands”
  • “The glass dome protects the delicate pendulum from draughts.”

Movement and Pendulum

The clock operates via a key-wound movement, which powers a torsion pendulum mechanism. This specific pendulum design utilizes four brass balls suspended from a thin wire. Rather than the traditional back-and-forth swing, the pendulum rotates about its vertical axis, causing the suspension wire to twist during operation.

This torsion mechanism allows for a significantly slower oscillation cycle, often taking between twelve and twenty seconds for a single oscillation. This efficient energy consumption is intended to enable the movement to operate for extended periods on a single winding, a characteristic for which this style of horological object is known.

Evidence for this section
  • “key-wound movement, brass torsion pendulum with four balls”
  • “pendulum suspended from a thin wire, which rotates about the vertical axis and thereby twists the wire”
  • “one oscillation usually takes twelve to twenty seconds, which is why the movement keeps running for a year or longer on one winding.”

Signatures and Condition

Both the dial and the internal clock movement are marked with the initials "CB". This mark identifies the piece as a product of the Badische Uhrenfabrik, a firm based in the Black Forest region of Germany that was also active in the manufacturing of radio receivers under the brand name Baduf during the 1920s.

Regarding its physical state, the auction description reports that the object is in a used condition that is commensurate with its age.

Evidence for this section
  • “dial and movement marked "CB”
  • “used condition commensurate with age, clock starts running”
  • “without key”

Open research questions

  • What is the significance or meaning of the "CB" mark used on this Badische Uhrenfabrik clock?
  • Are there surviving records of specific torsion clock models produced by the Badische Uhrenfabrik during the 1920s?

Source evidence

Recorded claims and source quotations for Badische Uhrenfabrik anniversary clock
FieldSource-reported valueSource quotation
MakerBadische Uhrenfabrik“Badische Uhrenfabrik”
Clock TypeTorsion pendulum clock“torsion pendulum clock, also known as anniversary clock”
MarkingsCB on dial and movement“dial and movement marked "CB”
Datingcirca 1920“circa 1920”
Diameter20 cm“D. 20 cm”
Height24 cm“H. 24 cm (with glass dome)”
ConditionUsed, operational“altersgemäßer, gebrauchter Zustand, Uhr läuft an”

Visible details

  • Pierced metal cresting above the clock dial
  • Four-ball brass torsion pendulum assembly
  • White enamel dial featuring black Arabic numerals
  • Glass protective dome housing the entire mechanism

Research qualifications

  • Key is reported as missing by the source
  • Specific mechanism performance longevity beyond initial start is not verified

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Badische Uhrenfabrik anniversary clock, torsion ball pendulum under glass dome, brass, circa 1920

Reviewed 2026-10-26 · Record 0f843e61d3

Terms in this record

Glossary explanations for terms named in this object’s record.

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