1930s Longines "Stop Second" Rare Turning Bezel & Black Tachymetre Dial

Longines, "Stop-Second", Cal. 12.68z powered, rare turning bezel, black dial with tachymeter scale, circa 1930s. It is powered with the Cal. 12.68z, which was modified from a three-hand model to a stop-second model with a 60-second counter. By setting the hour and minute hands to exactly zero and activating the chronograph, the time can be measured up to 12 hours. It also has a simple flyback function, and at a time when many manufacturers were creating chronographs by trial and error, this is a precious gem that shows the originality of Longines. The black gilt dial is beautifully preserved, and the tachymeter is displayed in a more detailed horizontal format (1000→900→800→700~). The tachymeter is displayed in a more detailed horizontal format from 1000 to 900 to 800 to 700.