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Important Modern & Vintage Timepieces

Hong Kong, May 10, 2020

LOT 314

Longines - “Hour-Angle” large aviator’s watch, so-called “Lindbergh”; stainless steel

Stainless steel, manual-winding, round-shaped, hour-angle, centre-seconds, large aviator’s wristwatch. Revolving bezel with blue and black enamelled 15 degrees graduation and graduated band; the ball-shaped winding-crown activates the hour and minute hands; the crown at 4 o’clock actives the revolving central dial.

Brand Longines, Saint-Imier

Model “Hour-Angle”

Reference 4365

Year circa 1945-1947

Movement No. 6 839 526

Case No. 23 228 / 3

Material stainless steel

Diameter 47 mm.

Caliber 37.9

Signature dial, case and movement

Accessories Original retailer’s papers

HKD 216,000 - 302,000

USD 27,600 - 38,500 / EUR 25,000 - 35,000 / CHF 27,600 - 38,500


Grading System
Grade: AAA

Excellent

Case: 2

Very good

Movement: 2 *
Dial: 2-01

Very good

HANDS Original


Notes

According to the papers accompanied this lot, dated April 8, 1947, the watch was delivered to the Longines agent, C. Lejhanec a Syn, Pardubice, Czechoslovakia.

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Longines “Hour-Angle” watch

The “Hour-Angle” system was invented by Philip Van Horn Weems (1889-1979) of the Annapolis Naval Academy, an authority in the 1920’s and 1930’s. He trained the famous Charles A. Lindbergh (1902-1974), who set the record for the first non-stop transoceanic flight.

The watch, as a navigational instrument for airplane pilots, is used in conjunction with a sextant and the appropriate nautical tables, to permits the rapid computation of the Greenwich hour angle, that is, the aircraft’s longitude.

The large ball-shaped winding-crown enables the watch to be wound by a pilot wearing gloves. It is practically impossible to build a commercial timepiece which will keep time to the exact second under the conditions met in a ship or in an aeroplane. The inevitable variation from true time necessitated an extra calculation in navigation to compensate for this chronometer error.

Weems noted that in an airplane moving at speeds of 200 to 300 miles an hour or more, the time required for calculating chronometer error was a danger that should be eliminated.

Since the high gear ratio made it impractical to set the second hand to the dial, Weems chose to set the dial to the hands. The seconds dial in the centre of the watch is rotated by turning a crown or by depressing the small stem on other models. For navigational purposes, Greenwich Mean time is indicated directly.

This model of watch was worn by Charles A. Lindbergh at Le Bourget Airport, near Paris, the airfield where he landed after opening on May 20-21, 1927, the Atlantic to aviation with his historic solo flight from New York.

The Longines Weems watch is made in two models. The smaller model is useful not only for sea navigators and aircraft pilots, but particularly radio broadcasters as well as others, such as civil engineers who require exact time.

Philip V. H. Weems is the holder of many patents of invention filed in the USA, including No. 2 008 734, dated July 23, 1935, where we find the idea of the rotating bezel (among many other technical inventions in this very complex patent).