19th century one-minute chronoscope "No. 3928" (signed Moritz Grossmann)

A Moritz Grossmann chronoscope was put up for auction at the Dr. Crott auction in November 2021. It is an extremely rare pocket watch even among existing examples. We would like to explore the details of this watch from the actual watch that has arrived in Japan.

A rare Grossmann pocket chronoscope

　There are not many pocket watches bearing the Karl Moritz Grossmann name still in existence. The Glashütte Museum houses complicated watches such as minute repeaters, but the majority of what remains are standard three-hand watches, large escapement models, and precision measuring instruments. Among these, Grossmann pocket chronoscopes (chronographs) are extremely rare.

　According to auction documents, the chronoscope No. 3928 brought to Japan this time was manufactured in the 1880s, meaning it was made just before Grossmann's sudden death in 85 while on a campaign tour in Leipzig.

　Unusually for a Grossmann pocket watch, the crown is located at 12 o'clock, but the base movement itself features a Savonette-type small seconds train wheel, a design widely shared in Glashütte at the time. This means that this watch has a fourth wheel at 3 o'clock. This drives the central seconds counter hand via an additional totalizer train wheel located below the dial. The pusher is located at 9 o'clock. It's an old-style one-push mechanism, with start/stop/reset controlled via a pull-operated column wheel, but it also has a sturdy brake lever, making the hand movement smooth.

　What's interesting is the way the three hands are stacked, with the additional second counter placed between the minute and hour hands. An enamel dial with slender Roman indices was standard at the time, but this chronoscope features a sunken dial with a split center.

　In fact, the successful bidder for No. 3928 was the Japanese subsidiary of Moritz Grossmann, and they are apparently planning a Japan Limited edition watch based on this dial. The actual watch will be on display at the boutique in Harimazaka, Tokyo, so if you're interested, why not stop by?