Presented for auction by Second Vintage The Longines Ultra-Chron represents a pinnacle of mid-century horological achievement, introduced to commemorate the brand's centennial anniversary with a groundbreaking high-beat movement. This striking example features a highly desirable black crosshair dial housed in a robust stainless steel cushion case, blending late 1960s aesthetic charm with serious chronometric pedigree. It stands as a testament to Longines' historical dedication to precision and bold design. Brand: Longines Model: Ultra-Chron Reference Number: 8317 6 Serial Number: 50944247 Movement: Automatic, Caliber 431, 36,000 bph, 25 Jewels Dial: Matte black crosshair dial displaying an even stardust patina, applied faceted indices, and applied Ultra-Chron logo Case Size: 35 mm (excluding the crown) Case Material: Stainless Steel Production Year: 1969 Condition: Excellent vintage condition with sharp case lines and attractive even dial patina Dial and Hands The dial features a matte black base anchored by a crisp white crosshair design, creating a highly legible and sophisticated layout. Over the decades, the black surface has developed a distinct and highly attractive stardust speckling, presenting an even, galaxy-like patina across the entire dial without any signs of localized moisture damage or heavy staining. The dial furniture is exceptional, featuring applied faceted silver-tone indices with black central inserts, an applied Longines winged hourglass logo, and the signature applied Ultra-Chron zig-zag emblem. A date window is positioned at three o'clock, framed by a stepped metallic border. The original baton hands feature black central stripes. Close inspection reveals visible oxidation and natural aging on the metallic surfaces of the minute and hour hands. The luminescent material on the hands and the small outer plots at the indices have aged to a dark tone, which is entirely consistent with the natural degradation typically seen on vintage black dials from this era. Case and Crystal The stainless steel cushion case is remarkably well-preserved, retaining strong factory lines and geometry. The upper surfaces display distinct radial brushing that contrasts beautifully with the highly polished case flanks. The case shows honest, light surface wear and minor handling marks consistent with careful vintage use, with no deep gouges or evidence of heavy over-polishing. The domed acrylic crystal is clear and well-preserved, offering an unobstructed view of the patinated dial. The original Longines signed crown, bearing the winged hourglass logo and brand name, is present and sits flush against the case side. The screw-down caseback is in excellent condition, featuring a crisp engraving of the Ultra-Chron logo and the outer case serial number 15977698. Movement Inside beats the renowned Longines Caliber 431, a high-frequency automatic movement operating at a rapid 36,000 beats per hour. The movement is beautifully finished and clearly marked with the caliber number 431, the serial number 50944247, and text indicating adjustment to four positions and temperature. The rotor is a work of art in itself, featuring the distinctive skeletonized Longines text cut out of the metal. Visually, the movement presents exceptionally clean, with bright surfaces and pristine screw heads. Exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. The timegrapher records a superb -10 to -12 seconds per day with strong amplitude. Strap The watch is fitted with a period correct black leather strap featuring a crocodile grain texture, complementing the dark dial and robust steel case perfectly. Condition This timepiece is in excellent vintage condition. The case remains robust with sharp transitions between the brushed and polished surfaces, retaining its factory intended shape. The dial's stardust patina is visually striking and uniform, presenting a highly desirable aesthetic for collectors of vintage black dials. The hands show expected surface oxidation and the lume has darkened naturally. The movement is exceptionally clean and running with tremendous high-beat precision. Dimensions The stainless steel case measures 35 mm in diameter excluding the crown. The cushion case geometry provides a substantial and comfortable presence on the wrist, wearing slightly larger than its dimensions might traditionally suggest. Remarks The Ultra-Chron remains one of the most historically significant high-beat watches of its era, representing a time when mechanical precision was the ultimate goal of the Swiss watch industry. Finding an example with a black crosshair dial, a sharp unpolished case, and an exceptionally well-preserved movement makes this a compelling opportunity for serious Longines collectors and vintage enthusiasts alike. History Launched in 1967 to celebrate the centenary of Longines, the Ultra-Chron was introduced to the public as the world's most accurate mass-produced watch. By utilizing a high-frequency 36,000 beat-per-hour escapement, Longines guaranteed an accuracy of a minute a month, a remarkable feat that rivaled the nascent electronic and tuning fork watches of the era. The distinctive zig-zag logo on the dial and caseback symbolizes the rapid frequency of the escapement, serving as a proud hallmark of Longines' chronometric mastery during the golden age of mechanical watchmaking. Payment and Shipping Payment must be completed within 1–3 days after purchase. Your watch will be professionally and very securely packaged, and shipped with tracking and insurance for your peace of mind. We ship via fast express service, with typical delivery in 1–4 business days (destination dependent). Note that with vintage watches, minor signs of wear, aging, or imperfections may be present and are considered normal for watches of this age. Please review all photos carefully before bidding. We strive to photograph each watch from multiple angles for the most accurate representation. The photos form an important part of the description. If there are any concerns of functionality or defects after delivery, make sure to contact us within 3 days of receiving the watch so we can assist you. As with all vintage watches, water resistance is not guaranteed. If you have any questions, feel free to contact us after the auction ends. / Second Vintage SKU: LON-LXX-0036