Observatory Dial Watches: Vintage Collection Guide

In this insightful article, quattro delves into the fascinating world of "observatory dial" watches, defining their unique characteristics and historical significance. He meticulously outlines the specific dial layout that distinguishes these precision timepieces, which were rigorously tested at renowned observatories worldwide. quattro's exploration provides a foundational understanding for collectors interested in the pinnacle of horological accuracy and the watches that achieved it.

What is commonly referred to as an "observatory dial" is the dial of a watch equipped with a precision movement, designed and adjusted to pass observatory tests, whether in Besançon, Neuchâtel, Geneva, Kew, Glashütte, etc.

Its most complete layout includes:

• A small seconds subdial at 9 o'clock;

• A sort of "subdial" at 3 o'clock with the name of the observatory where the movement was tested and the number of the Bulletin de Marche (certificate) it obtained.

But, as you will see below, there are many variations.

The most famous wristwatch with an observatory dial is the Patek Philippe reference 2458, made especially for Joe Ben Champion, Jr. (1917-1975), but I hope this thread will show that there are good reasons to look further.

credit: @positaque (1), personal photos (2-3), tp178.com (4) & Antiquorum (5)

credit: Antiquorum 

2/ NO. 46573 - yellow gold

3/ NO. 46582 - pink gold & stainless steel

credit: Antiquorum & Revolution (one before last only)

credit: Antiquorum & Hodinkee

D/ MASSENA LAB & RAÚL PAGÈS WATCHES

1/ PHILLIPS IN ASSOCIATION WITH BACS & RUSSO 1952 OBSERVATORY DIAL LIMITED EDITION BY MASSENA LAB AND RAÚL PAGÈS

2/ ABSINTHE

Here, interestingly, the focus is clearly set on chronometry, with the words "Observatory" and "Precision" on the 3 o'clock subdial.

credit: Massena LAB 

E/ EXAMPLES WITH ONLY A SMALL SECONDS SUBDIAL at 9 or 7 O'CLOCK (NO SUBDIAL at 3 O'CLOCK)

1/ PATEK PHILIPPE "M. BERTHAUDIN" ref. 96 CALATRAVA with OBSERVATORY TYPE DIAL -  No. 122898, case No. 612616. Produced in 1903, cased in 1936, sold on February 5, 1936

Marcel Berthaudin was one of the largest wine dealers in Geneva. Note that the "R" of BERTHAUDIN lost its "leg" on the dial and looks like a "P".

credit: Antiquorum & @the_watch_adviser

2/ PATEK PHILIPPE "E. BONNARD" ref. 96 CALATRAVA with OBSERVATORY TYPE DIAL -  No. 136786, case No. 612617. Produced circa 1930

Emile-Charles Bonnard was a French medical professor who retired to Switzerland and who requested this ref. 96 as a special order.

The "E. Bonnard" and "M. Berthaudin" together. To read more about these two watches, check the following article by Mark Kauzlarich on Hodinkee: Four + OneJohn Nagayama – Japan's Calatrava King


credit: John Nagayama aka @johnbehalf

3/ BERNHARD LEDERER TRIPLE CERTIFIED OBSERVATORY Central Impulse Chronometer 44, ref. CIC 9012.10.710

This watch, limited to 8 pieces, won the 2024 GPHG Chronometry Prize

Case: 44mm diameter x 12.2mm height – 904L stainless steel

On the lower surface of the small seconds subdial, three concentric decorative rings are engraved with the coordinates of the observatories where the watch has been tested for certification:

• Nearest to the centre are the coordinates for the Observatoire Chronométrique in Geneva (46.19607 | 06.12930), 

• followed by the French Besançon Observatory in the middle ring (47.24875 | 05.98963),

• and finally, the German Glashütte Observatory’s location (50.84780 | 13.78730) engraved closest to the edge.

credit: @watchesbylogan (1), @ch24pl, Monochrome (one before last) & Bernhard Lederer (last)