Zenith Automatic Cal. 133.8 "Bumper Movement", 1950s — view 1 of 6 — View 1 of 6 · Image: Craft & Tailored · original image source (opens another website in a new tab)

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Wristwatches · Wristwatch

Zenith Automatic Cal. 133.8 "Bumper Movement", 1950s

DocumentedDocumented from a dealer's listing; attribution and date as stated by the dealer.

Maker / attribution: Zenith (maker)
Date: 1950s
Historical period: Modern Mechanical Horology (1945 – 1969)
Country of origin: Switzerland
Object type: Wristwatch
Dealer: Craft & Tailored (dealer), Los Angeles
Stock no.: ZNTA1338
Credit line: Dealer listing, Craft & Tailored (ZNTA1338)
Catalogue title (original): 1950s Zenith Automatic Cal. 133.8 "Bumper Movement" (English)

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Record summary

Catalogued by Craft & Tailored (dealer), Los Angeles (stock number ZNTA1338), this is a wristwatch by Zenith, made in Switzerland, dated 1950s. The Atlas places it in the Modern Mechanical Horology period (1945 – 1969) of its Wristwatches collection. The record is illustrated with 6 photographs.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

Dealer description — Craft & Tailored

Zenith has created some truly iconic watches over the years, the El Primero being the most obvious. But well before the brand was known for announcing to the world the arrival of the first automatic chronograph, they were already building robust and beautiful timepieces the world over. Some, like this stunning Cal. 133.8 were so well made that you'd be hard-pressed to find a watch 50 years younger in as good of shape. Stock # ZNTA1338 Brand Zenith Style Automatic Model N/A Serial 886XXXX Size Men's Material Stainless Steel Dial Aged Millimeters 35 Bracelet 2pc Handmade Leather Strap CASE & BRACELET The stainless steel case measures in at 35 millimeters with a slightly wide sloped bezel and substantial lugs, giving the case a more powerful footprint than you might imagine from its on-paper measurement. Further, the lugs feature a beautiful tapered bevel and the overall condition of the case is, while worn, unpolished and razor-sharp. It is accompanied by a coordinating tan leather, 2pc handmade leather strap. DIAL & HANDS The dial is in fantastic condition with only slight spots of discoloration, having aged to a beautiful cream color. The watch features blued steel syringe-style hands, inlaid with golden honey-aged radium. ACCESSORIES

Historical context

Modern Mechanical Horology (1945 – 1969)

Tool watches for divers, pilots and astronauts; electric watches anticipate the electronic age.

The classic era of the mechanical wristwatch: dive watches, chronographs for motor racing and space flight, GMT watches for jet travel, slim dress watches, automatic calendars, and the rise of Japanese manufacturers alongside Swiss, American, German and Soviet industries.

Read the period in the timeline More wristwatches from this period Earlier: Golden Age of Mechanical Watchmaking

Atlas type guide

Automatic (self-winding) watches

Self-winding watches use the wearer's motion to wind the mainspring. Abraham-Louis Perrelet and Breguet made 'perpétuelle' pocket watches with oscillating weights in the late eighteenth century, but the principle only became practical in the wristwatch. John Harwood patented a bumper automatic in 1923; Rolex's Perpetual rotor (1931) winding in one direction, and later bidirectional rotors (Eterna, Felsa Bidynator), established the modern form. Micro-rotors (Universal Genève, Buren) and peripheral rotors made automatic watches thinner.

What to look for

A semicircular rotor turning 360° over the movement, or a 'bumper' weight that rebounds between springs.
'Automatic', 'Perpetual' or 'Self-winding' on the dial.
A sealed screw-back case, since automatic watches are wound less often by the crown.

Dating clues

Bumper automatics: 1923–c. 1955.
Full rotors: from 1931 (Rolex); widespread after c. 1950.
Micro-rotors: from 1954–1958.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

Mechanisms mentioned

Chronograph — Complication
Self-winding (automatic) mechanism — Component

Record completeness

Maker or attributionRecorded
DateRecorded
Place or countryRecorded
MaterialsNot in source
DimensionsNot in source
Narrative descriptionRecorded
Inscriptions / marksNot in source
ProvenanceNot in source
Several photographsRecorded

Editorial status: Documented — facts as published by the source; not independently verified by Atlas editors.

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Sources & image rights

Record source: Craft & Tailored (dealer), Los Angeles (opens another website in a new tab).

Image rights: © Craft & Tailored — dealer photographs; permission required (opens another website in a new tab).

Images are hosted by the Atlas for study and credited to their owner. Rights holders may request correction, credit changes or removal, or grant permission, via the editorial office.

Cite this record

"Zenith Automatic Cal. 133.8 "Bumper Movement", 1950s." Craft & Tailored (dealer), Los Angeles, ZNTA1338. Catalogue record in The Horology Atlas, WatchMuseum.org, https://atlas.watchmuseum.org/museum/zenith-automatic-cal-133-8-bumper-movement-1950s-2b23e2.