The Longines Twenty-Four Hours is fitted with calibre L704.3, a self-winding movement whereby the hands make one full circle of the dial in 24 hours. The stainless steel case has a diameter of 47.50 mm; the dial is matt black with 24 white Arabic numerals coated with Super-LumiNova and has a railway-track minute circle. The time is indicated by hands coated with Super-LumiNova and the watch has a centre seconds hand, all for ease of use, like the original model. There is a date aperture at 3 o’clock. A sapphire glass covers the dial and this timepiece also has a transparent caseback, with its own cover, which reveals the delicate details of the movement. The Longines Twenty-Four Hours is mounted on a black alligator strap and is water-resistant to 3 bar (30 meters).The Longines Twenty-Four Hours watch has a transparent caseback, with its own cover, which reveals the delicate details of the movement. The inside surface of the cover is engraved with the words “Re-edition of a Longines navigation watch exclusively made for Swissair navigators, 1953-1956“ plus the watch number.The Longines watch for Swissair navigators had been specifically manufactured for the Swiss national airline by Longines in the early 1950’s. It is fitted with a Longines calibre 37.9N with a centre seconds hand, which had been designed in the 1940s and used in Longines watches intended for pilots. The back cover of the steel case of the watch is engraved with the Swissair brand-name. Longines’ archives reveal that it was one of a series of 70 pieces manufactured between 1953 and 1956 exclusively for the Swiss national airline.
