DIAM. 44.5 mm. The Vacheron & Constantin aluminum watch was conceived in 1937 at the request of Vacheron Constantin agent Henry Banks Limited of Montreal, on behalf of the Canadian Aluminium Limited Companies. The watch, intended to mark 25 years of continuous service within the Aluminium group, was to have "real value, originality and at the same time, serve as a reminder of the great aluminum industry". A prototype was produced, whose case, dial, hands, bridges, and plates were made of aluminum, and the balance, springs, wheels and pivots of traditional materials, Testing showed that the new watch was as precise as the others in its category, made of more traditional materials. In 1938 Vacheron & Constantin delivered its first aluminum watches, which weighed approximately a quarter the WEIGHT of similar sized gold watches. By April of 1950 Vacheron & Constantin had delivered 271 examples of these watches. In later years aluminum became a mainstay of the watchmaking industry, thanks to its non-ferrous, antimagnetic qualities, as well as its lightness.