Venus Cal. 140 is a hand-winding chronograph movement. Measuring 13 ligne in diameter, it has an unusual 5-column wheel to control the chronograph function, and this mechanism resides entirely on the dial side of the movement. It began as a monopusher chronograph in 1935 before adding a second pusher later. It lasted in production until around 1949. It was succeeded by the more advanced Venus Cal. 150.
An unusual design, Cal. 140 places the hour and minute hands in a subdial at 12:00, a 30 or 45 minute chronograph register at 6:00, and a central chronograph seconds hand. This produces a notable 6-12 subdial arrangement with the look of a regulator.
Cal. 140 was used by a few Swiss and international brands. Due to the unusual dial layout, most are commonly called “regulator chronographs” though this is not strictly true. The most famous example was the Gallet Multichron, which was produced for many years and was used by aviators during World War II. It was also used by Berna, Doxa, Glycine, Juvenia, and even Ulysse Nardin.
More detail on the history of Vénus is available in the Grail Watch article, “The Rise of Vénus, Legendary Chronograph Maker“