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The Encyclopedia of Horology

Marine chronometer · Two-day marine chronometer

Zenith Bezel-Wound Marine Chronometer

Partially verified

This Zenith marine chronometer is a two-day navigational instrument from the mid-20th century. It is housed in a two-tier mahogany box featuring brass fittings and an integrated brass gimbal system with a locking mechanism. The movement is a three-quarter plate design with spotted gilt finish, featuring a large moving barrel and a unique bezel-winding system. The chronometer is wound by rotating the brass bezel and time is set by lifting and rotating it. A central steel winding gear is connected to a bowl containing the movement, which rotates on five spring-loaded ball bearings. The escapement is a club-foot Swiss lever with jeweled pivots. The regulation system includes a compensation balance, a blued-steel overcoil hairspring, and a polished steel regulator on a sub-platform. The silvered-brass dial displays Arabic numerals for hours 1-12, a 13-24 hour track, a sub-seconds dial, and a power reserve indicator with 'Haut' and 'Bas' markings.

The Zenith marine chronometer housed in its mahogany box, showing the silvered dial, power reserve indicator, and blue-steel hands.
The Zenith marine chronometer housed in its mahogany box, showing the silvered dial, power reserve indicator, and blue-steel hands. — Pieces of Time. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
zamanito.com
Category
Marine chronometer · Two-day marine chronometer
Maker / attribution
Zenith
Reference
Not recorded
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
Mid-20th century
Source-reported place
Switzerland
Source-reported serial
25036

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

Movement and Escapement

The movement is a three-quarter plate configuration finished with spotted gilding. It incorporates a keyless design utilizing a large moving barrel. A distinguishing feature is the bezel-winding mechanism, which enables the chronometer to be wound by turning the brass bezel, while lifting and rotating it allows for time setting.

The oscillation system is mounted on a sub-platform and comprises a compensation balance paired with a blued-steel overcoil hairspring. The escapement is a club-foot Swiss lever, with jeweled end-stones fitted to both the lever and escape wheel pivots, controlled by a polished steel regulator.

Evidence for this section
  • “موتور ساعت دارای صفحه سه‌چهارم طلایی با پرداخت خال‌دار (spotted gilt)”
  • “ساختار فنی این ساعت به سیستم کوک از طریق زهوار برنجی مجهز است”
  • “چرخ‌دنگ اهرمی سرچکشی (club foot lever) است که محورهای اهرم و فرار آن دارای سنگ‌های انتهایی هستند”

Dial and Navigation Features

The dial is constructed from silvered brass and features clearly legible Arabic numerals. It indicates the primary hours 1 through 12 in a large format, with a secondary track for 13 through 24 hours. The dial also includes a sub-seconds register and a power reserve indicator marked 'Haut' and 'Bas'.

Blue-steel hands are used for time indication. The movement is mounted within a brass gimbal system designed to maintain equilibrium at sea, which includes a mechanical lock. The entire assembly is housed in a two-tier mahogany box featuring brass corner reinforcements and a shallow upper lid.

Evidence for this section
  • “صفحه ساعت از جنس برنج نقره‌اندود و امضاشده است و شامل عقربه‌های فولادی آبی‌رنگ”
  • “زیرصفحه ثانیه‌شمار و نمایشگر ذخیره انرژی می‌باشد”
  • “این مجموعه درون سیستم تعلیق ژیمبال برنجی همراه با مکانیزم قفل قرار داشته”

Construction and Technical Details

The instrument employs a unique arrangement where a central steel winding gear connects to the movement holder. This bowl-shaped support facilitates smooth operation through the use of five spring-loaded ball bearings positioned along the edges, allowing the movement to rotate freely as part of the bezel-winding sequence.

Technical design follows established marine chronometer practices for the period, prioritizing accurate timekeeping for navigational calculations. The combination of the two-day power reserve and the stabilized gimbal suspension reflects the requirement for performance under maritime conditions.

Evidence for this section
  • “این کاسه به کمک پنج بلبرینگ ساچمه‌ای فنردار در لبه‌های خود به آزادی به دور موتور می‌چرخد”
  • “ابزارها با بهره‌گیری از سیستم تعلیق ژیمبال برای حفظ تعادل در برابر امواج”

Open research questions

  • Was this Zenith chronometer movement produced in-house or sourced from a specialized ebauche maker?
  • Are there specific naval records or ship logs associated with this serial number?

Source evidence

Recorded claims and source quotations for Zenith Bezel-Wound Marine Chronometer
FieldSource-reported valueSource quotation
DateMid-20th century“اواسط قرن بیستم”
Winding MechanismBezel-wound“سیستم کوک از طریق زهوار برنجی”
EscapementClub-foot Swiss lever“چرخ‌دنگ اهرمی سرچکشی (club foot lever)”
Power ReserveTwo-day duration“کرونومتر دریایی دو روزه”
Case MaterialMahogany with brass“دوسطحی از چوب ماهون با بست‌های برنجی”

Visible details

  • Silvered-brass dial with dual 12/24 hour indicators.
  • Movement plate features spotted gilt decoration.
  • Mahogany case with brass hardware and gimbal suspension.
  • Serial number 25036 visible on the movement plate.

Research qualifications

  • The source attributes the object to the mid-20th century without specifying a precise year.
  • The source does not explicitly verify the authenticity of the case as original to the movement.

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

Consulted source

Bezel Wound Marine Chronometer

Reviewed 2026-11-02 · Record 7a84e3ff0a

Terms in this record

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

Other two-day marine chronometer records