Borgel-Type Screw-Case Officer's Wristwatch

Like the plainer wire-lug trench watch, this type takes a small pocket-watch-derived movement — enamel dial, sub-seconds, keyless winding inherited from pendant practice — and mounts it for wrist wear. What distinguishes it is the case: rather than a simple hinged or snap-back case with soldered wire lugs, the movement sits in a case body sealed by screwing the whole front assembly into the back, a construction patented by the Geneva case-maker François Borgel in 1891.

The screw construction gave meaningfully better resistance to dust and moisture than a plain hinged case, which mattered directly to an officer wearing the watch in the field rather than in a waistcoat pocket, and the type is one of the clearest illustrations that the early wristwatch trade was actively re-engineering pocket-watch cases for wrist conditions, not merely adding lugs to them.

Borgel's screw-case patent long predates the First World War and was originally applied to pocket and early wristwatch cases sold through the 1890s and 1900s. Wartime demand for a wrist-worn watch that could survive field conditions gave the screw-case construction a specific new market among combatant officers, who bought or were issued such watches privately as often as through formal supply.

As with wire-lug watches generally, the wristwatch only became broadly acceptable for men because of this military use; before the war a man's watch was expected to live in a waistcoat pocket, and the screw-cased officer's watch is part of the evidence for exactly when and why that expectation changed.

The screw-case construction is the design's defining feature: unscrewing the bezel/crystal assembly, or the whole movement carrier, from the case body is a fundamentally different servicing access from a hinged snap-back, and the two should never be forced interchangeably.

Wire or soldered fixed lugs were added to what was originally pocket-watch case geometry; as with plainer trench watches, lug repairs and replacements are common and should be documented rather than disguised.

Movements are small Swiss trade calibres, frequently unsigned or marked only with a calibre or supplier code, consistent with general trade assembly rather than a single named manufacturer.

Cylinder-escapement examples generally predate or are cheaper than lever-escapement examples of the same case pattern; the escapement should be checked directly rather than assumed from case style alone.

Genuine Borgel-pattern cases usually carry the Borgel trademark (often a stylised key or the Borgel name) stamped inside the case back or on the movement carrier; this should be checked before attributing a case to the pattern.

British import hallmarks, where present, date the case reliably; the movement inside can be somewhat earlier through normal trade stock turnover.

The screw threads are a wear point; cross-threading from careless handling is a genuine and irreversible risk and is a common cause of a case that will no longer seal or close properly.

Enamel dials crack radially from the centre hole and chip at the edge; hairline cracking on its own is age, not damage, in a dial of this date.

Radium luminous material, where fitted to campaign examples, should be treated as a low-level radioactive hazard and left undisturbed.