Harmony 5300S-000R-B124

Whether it is used to time the cooking of an egg or the duration of a flight, the chronograph is one of horology’s most popular complications – but not all of them are created equal. What many pricier chronograph movements have in common is the column wheel, in essence the on-off switch for a chronograph mechanism, controlling its start, stop and reset functions.

A carved Maltese cross marks the column wheel of Vacheron Constantin’s in-house chronograph Calibre 3300 (near the bottom of the movement, above the words “Swiss Made”).

Shaped like the turret of a castle, this mechanism is sometimes called the castle wheel. The levers of the chronograph mechanism move in and out of the columns of the wheel as the chronograph is activated. Vacheron Constantin’s newest in-house chronograph movements, including the caliber 3300 found in the Harmony Chronograph, all feature column wheels decorated with a relief Maltese Cross, the company logo.

The latest Vacheron Constantin Harmony Chronograph, a monopusher chrono with a pulsometer scale.