Amazingly well preserved Longines Lindbergh Hour Angle watch with red number bezel. According to the Longines Archive in Switzerland, this stainless steel reference # 4038.was invoiced on 3 June 1938 to Longines–Wittnauer Company, Inc., which was at that time the Longines agent for the USA.. There are matching serial numbers on the 12.68z movement and also the case. The thick flat-top glass crystal has chips, and appears to be original. The two crowns also appear to be original. The watch is signed Longines on the dial, case and movement.
As indicated on the rear of the watch, the hour angle watch was designed by Col. Charles A. Lindbergh and given patent number 1923305. Working with Longines, who was then the official supplier to the Fédération Aéronautique Internationale, Lindbergh expanded upon the original Weems design, to allow longitude to be calculated based on GMT. The Hour Angle watch features a sextant-like rotating bezel and an inner disc that could be synchronized to the second from a radio time signal.
- Head diameter excluding the winding crown: 33mm
- Top to Bottom: 40mm
- Lug Spacing for Strap: 16mm
Case: Reference 4038 stainless steel with snap back engraved Invented by Col. Chas. A. Lindbergh U. S. Patent Nos. 1923305, silver rotating bezel calibrated for 1 hour = 15° Earth's rotation, red and black enamel numerals
Dial Detail: Original and not modified - Silvered with fixed 60-minute ring calibrated for 180° Earth's rotation, roman numerals, enclosing rotating 60-seconds disc calibrated for 15' Earth's rotation, blued steel hour, minute and seconds hands
Movement Caliber: Longines 12.68z, 15 Jewel, Manual Wind
Condition: Serviced and ready to wear