Reference:1491

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Prince → 1491

The 1491 is the Brancard Jumping Hour Prince — Rolex's only catalogued rectangular wrist with a heures sautantes display, produced from 1930 into the mid-1940s. The hours read through a digital aperture at twelve o'clock, the minutes track around the dial, and the sub-seconds register sits at six. The case is a flared Brancard form, visually similar to the 1490 but slightly thicker because the jump-hour module added depth to the standard Prince movement architecture. That dimensional difference is the single most reliable authentication anchor: a 1491 case is deeper than a 1490 case, and the deeper case carries a distinct case-number sequence, often stamped with an explicit "HS" suffix (Heures Sautantes) on the inside of the caseback. The complication earned the watch the "1491HS" designation in dressy white-gold and bicolor sub-runs, with factory case stamps like F2149HS and F220 confirming the suffix is applied at the case level, not just by auction-catalog convention. The watch was commercially short-lived — readers found the jumping-hour layout difficult to interpret, the Depression and Rolex's own Oyster Perpetual marketing absorbed catalog momentum, and the manufacturing complexity discouraged sustained production. Surviving examples are scarce; collector reports place the surfaced population in the low hundreds, with public auction examples surfacing roughly once per decade for the rarest configurations.

Rolex Prince 1491HS two-color 18K gold jumping hour
1491HS two-color 18K gold (Bonhams sale 29152 lot 6, c.1930) — jump-hour aperture at twelve, sub-seconds at six

Core facts

detail value
reference 1491 (1491HS for the dressy white-gold / bicolor sub-runs with the HS factory case stamp)
family Prince Brancard with jumping-hour complication
production 1930–1945 (earliest documented Glasgow imports 1930; latest documented original retail 1945, Bucherer invoice on Antiquorum 2008 lot 692)
case shape flared Brancard "stretcher," like the 1490 but with greater case depth to fit the jump-hour module
case dimensions approximately 22–24 mm × 34–35 mm body (Bonhams); approximately 25 × 42 mm with horns (Antiquorum). The dimensional split across catalog houses is consistent with measurement convention rather than two case sizes
case construction three-piece, polished, deeper than 1490
crystal acrylic
crown onion / pull-out, non-screw
lug style integrated flared, period-strap fit
bezel smooth, polished
caseback marking factory-stamped reference + serial; HS examples carry an "HS" suffix on the caseback (e.g. F2149HS, F220) but this suffix is often dropped on factory papers, accounting for catalog inconsistency
movement Aegler shaped, 7½′′′ (or 7′′′) base architecture with jumping-hour module mounted on the standard Prince base — the module is Aegler-built, not sourced from a complication specialist
caliber labels "7½′′′ Extra Prima Observatory" (Antiquorum, multiple sales); "Cal. 350 T.S." (Phillips); "15j Observatory" (lower-grade variants). Same base movement, different grade tiers
jewels 15 (gold-cased examples) / 17 (HS + steel/silver examples)
beat rate 18,000 vph
power reserve approximately 50 hours
escapement lateral lever
balance bimetallic, with Breguet overcoil hairspring
adjustments 6 positions, Observatory-grade
dial layout digital hour aperture at twelve / minute track around the dial / sub-seconds register at six
materials documented stainless steel, sterling silver, 9K yellow / white / bicolor, 18K yellow / white / bicolor; platinum is widely cited in editorial sources but is NOT corroborated in the auction record (the platinum claim likely cross-attributes from the 1490)
price band (hammer) GBP 4,812 (9K yellow, Bonhams 2019) → GBP 6,247–12,160 (stainless, Bonhams) → CHF 10,000 (Christie's Geneva 2018) → USD 11,875 (Christie's NY 2020) → CHF 17,825–18,400 (Antiquorum HS 1997–2000) → EUR 27,028 (Artcurial 1932 bicolor) → CHF 34,500 (Antiquorum 1990 white+yellow HS) → CHF 44,000–50,000 estimate (Antiquorum 2008 white-gold HS pair). Dealer ask USD 44,445 (Chrono24) corroborates the high end

Where it sits in the line

The 1491 launched in 1930 as the complication-bearing companion to the standard 1490 Brancard. The two references share the flared Art-Deco rectangular case shape and the same Aegler shaped-movement family at the architectural base, but the 1491 carries a jumping-hour module mounted on top of the standard Prince movement. The module added enough mechanical thickness that the 1491 case had to be deepened to accommodate it. Rolex assigned the 1491 a separate case-number sequence rather than fitting the module into 1490-stamped cases, and on the dressier white-gold and bicolor sub-runs the casebacks were stamped with an explicit "HS" suffix (Heures Sautantes). The Watchprosite collector record carries the load-bearing technical sentence: the HS module is "slightly thicker than the regular Prince movement and thus had a special case number, and most had the letters HS in the reference number."

The Brancard Prince family runs the 971, 1490, and 1491 in parallel through 1930–1945, with the 1862 and other Classic Princes alongside them on a different case shape. Where the 1490 dominated period Rolex advertising and the 971 carried the chronometer-grade marketing, the 1491 was a complication showcase — technically distinguished, rare in the catalog, and never marketed at the same volume. Two auction-record signals corroborate the short production: the 1491 surfaces in modern auctions at roughly the same depth as the platinum 971 (a configuration documented in single-digit examples), and the population proxy from Watchprosite places surviving 1491s in the low hundreds, with the dressier 1491HS configurations surfacing once per decade or less.

A possible sibling reference deserves naming carefully. Robb Report identifies a ref. 1571 "Railway Prince" with the same jumping-hour complication in a different Prince case form; the attribution is not corroborated by other primary sources and should be treated as an open lead. Phillips's 2016 Beyer-signed silver jump-hour Prince is catalogued as ref. 1490, while Antiquorum's similar-layout examples are catalogued as 1491HS — Phillips and Antiquorum disagree on the reference number for visually identical configurations. The most defensible reading is that any Brancard Prince with the jumping-hour layout is a 1491 (with HS suffix on the dressier sub-runs), and the Phillips 1490 attribution is a catalog reading-from-paperwork-only ambiguity stemming from the HS-on-caseback-but-not-on-papers convention.

The jumping-hour mechanism

Rolex Prince 1491 18K Glasgow 1930
1491 18K yellow gold, Glasgow Import mark 1930 (Bonhams sale 29152 lot 23) — front view shows the jump-hour aperture at twelve and the sub-seconds register at six

The Aegler shaped-movement family that powered the standard Prince — Cal. 300, Cal. 350, Cal. 7½′′′ T.S. 300 — receives a jumping-hour module on the 1491. The module is Aegler-built rather than sourced from a complication specialist (Audemars Frères, Le Coultre, or one of the period jump-hour module makers like Hahn or Cortébert). It mounts on top of the standard Prince base movement and consists of an hour disc carrying the twelve hour numerals, an instantaneous-jump mechanism that advances the disc one position per hour at the moment the minute hand reaches twelve, and a small aperture cut into the dial at the twelve o'clock position through which one numeral at a time is visible.

The module added enough thickness to the standard movement that the 1491 case is deeper than the 1490 case. This dimensional difference is the canonical authentication tell — a Brancard claimed as a 1491 that has the same case depth as a 1490 is either a transplant (1490 case fitted with a later jumping-hour module) or a misidentified 1490 with a refinished aperture-style dial. The 1491 case is also distinguished by its case-number sequence: F-prefix factory stamps are documented on multiple HS examples (F2149HS at Antiquorum 2008 lot 692, F220 at Bonhams 2024), and the "HS" letters appear on the caseback even when the same letters are absent from accompanying factory papers.

Three documented mechanism failure modes are worth naming because they shape what to expect from a service-untouched 1491. First, the jump impulse spring weakens with age and produces a "lazy" disc advance — the disc rotates partially rather than snapping cleanly to the next numeral. Second, the disc retention pawl wears at the impulse face and produces hour-disc jitter under wrist movement. Third, the dial aperture wears at its mounting points and the disc misaligns with the aperture window, showing fragments of two numerals simultaneously. Watchmaker reports indicate a 1491 that "sets time but the hour disc disengages immediately" is symptomatic of broken impulse spring engagement, a known service intervention rather than a hidden fault.

The base movement runs at 18,000 vph with approximately 50 hours of power reserve, the same parameters as the standard Prince calibers. Adjustment is to 6 positions, Observatory-grade. Catalog descriptions vary across auction houses — Antiquorum and Christie's typically write "7½′′′ Extra Prima Observatory quality"; Phillips writes "Cal. 350 T.S. 15j"; some lower-grade examples carry "15-jewel Observatory." Forum collector consensus reads these as the same base architecture under three different grade-and-house labels. There is no separate caliber number for the jumping-hour module itself — the module is an addition to the standard Prince base rather than a distinct movement.

Dial layout

The 1491 dial reads in three zones rather than two. The hours appear in a small square or circular aperture at twelve o'clock, displaying one numeral at a time as the disc advances. The minutes track around the perimeter of the dial, marked at standard five-minute intervals or in finer detail depending on dial variant. The sub-seconds register sits at six o'clock, the same position as on the standard duo-dial Prince. The result is a dial that reads less intuitively than a conventional analog wrist — the user must look at three discrete zones to read the time, and (per the Watchprosite collector record) the layout is "very difficult to actually tell the time."

Documented dial configurations on surfaced 1491 examples:

  • Silvered dial with painted Arabic minute track, hour aperture at twelve, sub-seconds at six — the most common configuration on 9K and 18K examples.
  • Silvered dial with applied Breguet-style minute markers, hour aperture, sub-seconds — typical on dressier white-gold and bicolor examples.
  • Two-tone sector dial with hour aperture and sub-seconds — late 1930s Art-Deco geometric variants.
  • Bucherer-double-signed dial — Antiquorum 2008 lot 692, white-gold 1491HS with original 1945 Bucherer invoice. The only documented retailer-double on a 1491.
  • Beyer Zurich-signed dial — Phillips 2016 lot 89, silver Brancard with jumping hour. Phillips catalogued as ref. 1490 but the layout matches Antiquorum's 1491HS examples; the attribution dispute is unresolved at the catalog level.

Hand styles are limited: the minute hand is typically blued steel pencil or sword form, and the sub-seconds hand is blued steel. The hour disc itself uses Arabic numerals on most surfaced examples, with Roman numerals on a small minority of dressy late-1930s configurations.

Authentication

Authentication of a 1491 follows the Prince-family workflow with three reference-specific differences.

  1. Case depth versus the 1490. A genuine 1491 case is measurably thicker than a 1490 case because the jumping-hour module sits on top of the standard Prince base movement. A side-by-side caliper measurement against a known-correct 1490 is the cleanest authentication check. A Brancard claimed as a 1491 with 1490-equivalent case depth is either a 1490 with a refinished aperture-style dial (no jump module installed) or a 1490 case fitted with a later jump-hour mechanism in service.
  1. Caseback HS suffix. Dressy white-gold and bicolor 1491HS examples carry "HS" on the inside of the caseback, sometimes with a factory case stamp (F2149HS at Antiquorum 2008, F220 at Bonhams 2024). The suffix is often dropped on accompanying factory papers, so a 1491 with HS-marked caseback but plain "1491" on the warranty card is consistent with factory practice rather than evidence of mismatched paperwork. A 1491HS-marked caseback on a thinner 1490-depth case is a transplant.
  1. Movement-to-module match. The jumping-hour module should be Aegler-built, recognizable from the integrated module-on-base architecture and the period-correct Aegler finish. A jump-hour module by Le Coultre, Hahn, Cortébert, or any other period maker under a Prince case is a transplant. The 1491 movement bridge should carry the standard Prince signing (Aegler or "Rolex Prince" depending on grade tier), with the module mounted to the rear of the bridge.

Three reference-broad checks also apply. The crown should be onion-form push-pull and signed Rolex; gold cases carry gold crowns. Glasgow / Edinburgh import hallmarks date the case to a single year — the surfaced 1491 corpus carries 1930 Glasgow imports, with Glasgow / continental hallmarks documented through the late 1930s. Caseback engravings should be factory-stamped; hand-engraved presentation marks (the 1932 caseback engraving on the Artcurial bicolor example) sit alongside factory stamping rather than replacing it.

The Datejust precedent claim

A speculative claim runs through the Prince literature: the 1491's hour aperture is the conceptual ancestor of the 1945 Datejust window. Jake Ehrlich (Rolex Magazine) and rolexencyclopedie.nl independently propose the lineage. The argument is structural — both designs cut a window into the dial, both display a single value at a time through the window, both rely on a disc that advances by mechanism rather than by hand. The connection is plausible but not corroborated by primary Rolex documentation; the Datejust window is conventionally credited to a separate development thread within Rolex's Perpetual research rather than to the Prince's jumping-hour module. Treat the claim as a two-source editorial speculation rather than established fact.

Auction record

year venue configuration hammer / estimate
1990 Antiquorum white + yellow gold 1491HS CHF 34,500
1997–2000 Antiquorum (multiple) 1491HS various CHF 17,825–18,400
2008 Antiquorum (lot 692) white-gold 1491HS Bucherer-retailed, 1945 invoice, F2149HS case stamp est. CHF 44,000–50,000
2018 Christie's Geneva (lot 113) 18K bicolor 1491HS CHF 10,000
2019 Bonhams 9K yellow, 1930 GBP 4,812
2020 Christie's NY (lot 130) 18K bicolor with Observatory cert 1935 USD 11,875
various Bonhams stainless GBP 6,247–12,160
2024 Bonhams 1491HS two-color 18K, case F220 est. GBP 10,000–15,000
various Tajan / Artcurial / Cortrie 9K bicolor / silver EUR 7,800–19,500
~2010s Artcurial bicolor with 1932 caseback engraving EUR 27,028
current Chrono24 (dealer ask) various 1491HS USD 44,445

The 1491 commands a 2–4× premium over a comparable steel or yellow-gold 1490, and a 5–10× premium in white-gold or bicolor HS form. Phillips Geneva carries no documented 1491 lots in their public archive — the reference's auction representation runs through Antiquorum and Bonhams, with Christie's, Artcurial, and Tajan filling out the European tier. Sotheby's GE1604 lot 135 from 2016 (an unsold 1491 estimate) is cited via aggregator only and lacks direct catalog documentation in the public record.

Sources

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