Patek Philippe Ref. 738 Pocket Chronometer

Technical characteristics

Type

Deck watch

Maker

Patek Philippe

Model

Deck-Watch

Reference

738

Balance Type

Guillaume balance

Case Material

0.925 silver

Certification

First Class Bulletin de marche

Place recorded

Switzerland

Movement Caliber

19'''

Date of Manufacture

1921

Maker / attribution

Patek Philippe

Design

Case and Dial

The watch is presented in an open-face case constructed from 0.925 silver. It features a round profile designed for functional use as a deck watch. The exterior maintains a simple, utilitarian aesthetic consistent with its intended application for precision scientific observation and shipboard navigation. The silver-colored dial displays large, suspended Arabic numerals. The time is indicated by blued steel spade hands, with a subsidiary seconds register positioned at the 6 o'clock mark. Both the dial and case exhibit minor signs of wear, including light scratches, as noted in the auction description.

Visible features

• Silver-colored dial with subsidiary seconds at 6 o'clock • Blued steel spade hands • Movement bridge bears Patek Philippe & Co signature • Visible index regulator with swan-neck spring and micrometric screw

Movement and Escapement

The movement is a rhodium-plated 19''' caliber utilizing a going barrel and a straight-line lever escapement. Chronometric precision is facilitated by a bimetallic compensated Guillaume balance, which incorporates gold poising screws and a blued steel hairspring with a terminal curve. Regulation is managed by a polished steel index system equipped with a swan-neck spring and a micrometric screw. The movement was adjusted by H. Wehrli of Geneva and displays the Poinçon de Genève hallmark in two locations, indicating its adherence to established quality standards at the time of assembly.

Observatory Performance

In 1934, this specific chronometer participated in a timing contest at the Astronomical Observatory of Geneva. It achieved a First Class Bulletin de marche and an honourable mention, scoring 624 points out of a possible 1,000. The watch was produced in 1921 and eventually sold on January 30, 1942, as verified by the Extract from the Archives provided with the object. Copies of the original observatory bulletins from 1932 to 1934 accompany the watch to document its historical performance record.

Identification

Reference

738

Serial number

191 008

Source note

Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.

Catalogue references

No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.