Clamshell cases were introduced in the 1930s as one of the earliest solutions to make wristwatches waterproof. Instead of the traditional screw-down caseback, these cases used four small screws placed along the sides to clamp the back and middle case together, compressing an internal gasket to ensure water resistance.
The system, patented by Schmitz Frères in Switzerland, was adopted by several manufacturers of the time, including Gallet, Mido, Movado, Mulco, and Tavannes, mainly for chronographs and professional-use watches.
This Tavannes is a chronograph equipped with this rare and sought-after case construction. It is a rather uncommon watch, and its condition is excellent: the two-tone dial shows only light signs of wear, perfectly normal for its age, but all the scales remain crisp and fully legible. The case, measuring 38 mm in diameter with a 20 mm lug width, is in outstanding condition with no dents or notable defects. The manually wound movement runs perfectly. All components are original and period-correct, except for the central chrono hand which has been changed over time. The watch is fitted with a generic buckle on the strap.
A fantastic oversize and rare chronograph to wear and enjoy!