The Patek Philippe ref. 2540 is one of the earliest references to house the manufactures very first self-winding calibre, the 12-600 AT. With its elegant square case, facetted lugs and Gbelin-signed dial, it combines a range of distinctive, characterful features.

The reference

The reference 2540, believed to have been in production between 1954 and 1960, was Patek Philippe's first square wristwatch fitted with an automatic movement.

This particular example is further distinguished by its double-signed dial bearing the name of the Swiss retailer, Gbelin. Based in Zurich, Gbelin is one of the oldest watch retailers in Europe, having operated since 1854. Historically, they shared a close relationship with Patek Philippe, having printed their name on the dial of some of the manufactures most sought-after models.

The Design

This yellow gold Patek Philippe ref. 2540 features a square case, measuring 31mm in either direction, which wears larger on the wrist, on account of and characterful lugs. The hallmark found on the inside of the caseback, a key with the number 26, attributes the case to Ponti, Gennari & Cie, a Geneva-based casemaker, who made several cases for Patek Philippe.The case and lugs are well preserved, with crisp hallmarks visible on the right-hand side of the case and behind the top left lug. One of the distinctive features of the reference, the original crown is signed with two, back-to-back P letters, for Patek Philippe. This style of crown was introduced for the calibre 12-600 AT, and can also be found on .

The silver dial is equally well-preserved, with the Patek Philippe Genve signature made of raised enamel appearing slightly elevated. The Gbelin signature is applied at 6 oclock, just below the hands and above the subsidiary seconds track. The hours are indicated with the help of applied gold indexes, with those at 12, 3 and 9 oclock being oversized compared to the others.

The Movement

The watch is powered by the Patek Philippe's very first self-winding calibre, the 12-600 AT. Launched in 1953, the 12-ligne movement is considered by many as one of the finest automatic calibres ever made, with around 7,100 believed to have been produced. The 12-600 AT features Patek Philippes Gyromax balance wheel, first introduced two years prior, which is an adjustable inertia balance. The Gyromax remains one of the manufactures trademarks, to this very day. Aiding the Gyromax wheel is a swan neck regulator and self-compensating Breguet balance spring. Reminiscent of Patek Philippes mid-century hand-wound movements, separate cocks are used for the balance wheel, escape wheel, and fourth wheel.

In a period brochure from Patek Philippe, the movement is described as such, The Patek Philippe Automatic watch is treasured for its luxurious elegance, the beauty of its lines and its enduring accuracy. With good care, and after personal adjustment to your own wrist, the maximum variation is only 1 second in 24 hours. This level of accuracy, especially in 1953, speaks to the technical prowess of the 12-600 AT.

The rotor, possibly the very first decorated rotor in history, features an intricate engine-turned motif, alongside a Patek Philippe crest in the centre. Bearing the Geneva Seal, the movement is beautifully finished, with exquisite chamfering on all angles, countersinks, polishing and decoration, in the form of Geneva striping. This level of hand-finishing is all the more impressive, considering the watch came with a closed caseback, and it would be several more decades until open casebacks even became a practical reality.

The Set

This Patek Philippe ref. 2540 in yellow gold is accompanied by its original box and Extract from the Archives, which confirms production and sale of the watch in 1957. It comes on our light grey saffiano strap, with a matching yellow gold Patek Philippe tang buckle. It also comes with a Patek Philippe black alligator strap.

Viewings can be arranged in Central London by appointment.

Closer look