Longines & Wittnauer

• cal. 16''' 15 jewelled nickel-finished lever movement, cut bi-metallic compensation balance • white enamel chapter ring with Breguet numerals, central silvered matt disc calibrated for the seconds, rotated by turning the eccentric crown in the band, blued steel moon-style hands, sweep centre seconds • stainless steel oversized case, oversized ball-shaped and fluted crown, hinged back • case and movement signed by Longines, dial signed by Wittnauer and Longines

Please note that the movement has not been checked for timekeeping accuracy and Sotheby's will not be held responsible for any repairs should they be required. The movement is running. Dial in good condition with intact enamel, please note that the second hand has been changed. Hands are gently worn. Case with usual scuffs throughout.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. All dimensions in catalogue descriptions are approximate. Condition reports may not specify mechanical replacements or imperfections to the movement, case, dial, pendulum, separate base(s) or dome. Watches in water-resistant cases have been opened to examine movements but no warranties are made that the watches are currently water-resistant. Please note that we do not guarantee the authenticity of any individual component parts, such as wheels, hands, crowns, crystals, screws, bracelets and leather bands, since subsequent repairs and restoration work may have resulted in the replacement of original parts. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. In particular, please note it is the purchaser's responsibility to comply with any applicable import and export matters, particularly in relation to lots incorporating materials from endangered species.NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

**Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping.

Important Notice regarding importation into the United States of Rolex watches
Sotheby's cannot arrange for the delivery of Rolex watches to the United States because U.S. laws restricts the import of Rolex watches. The buyer or a designated agent may collect the property in the country of sale."

The developer of this navigation watch was the lieutenant commander for the United State Navy P.V.H Weems.
In 1929, Navy Captain Phillip Van Horn Weems in conjunction with Longines (and Wittnauer) developed the Weems Second-Setting Watch for nautical navigation. Given the turbulent cockpits and the thick gloves needed for altitude flying, the Weems was typically oversized.

The second-setting watch owning to the low gear ratio between the hour and minute hands as compared with the second hand of an ordinary causes, no provision is made for setting the second hand of an ordinary watch. This means that the watch set to the correct hour and minute may still be in error as much as 30 seconds, which, near the equator, represents an error in longitude of 7.5 miles. The second-setting watch was devised to permit the exact second to be set, thus avoiding the correction ordinarily required by the navigation watch. This is done in the standard model by rotating an inner seconds dial. The hour and minute hands are set in the usual way. When the minute hand is properly set, it should of course be exactly at a minute division when the second hand is at 60.

Pilots could listen to the time signals from the Radio.Time.Signals. from 5 minutes before each hour to the hour, the silence after 50^th seconds of the fifth minute indicates at once the number of minutes of signal yet to be sent. The rotating inner dial displayed the correct minutes and graphically showed the margin of error from the original set time.

Air navigation by: Weems, Philip Van Horn, Published in 1943 pages 299 to 304