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     II W.W.      
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UPDATED MAY 2018 CLOCKS FOR SALE ME - CONTACT

LONGINES-WITTNAUER

No other clock brand has been involved as much as Longines in the creation of specific machines for pilots and planes, manufacturing more than 100 exclusive pieces.

 

Ernest Francillon founded Longines in 1866 in Imier, Switzerland. Albert Charles Wittnauer, introduced in America the brand Longines.

In 1912 Emile Wittnauer, in one of the trips to his factories in Switzerland, hired a boy less than 20 years of age called John PV Heinmuller, his great passion for planes made him be known by the nickname of “Aero one”.

 

During the I World War, the great knowledge he possessed, made possible to produce a complete range of clocks, altimeters, compasses, turn and bank indicator, placing Wittnauer as one of the first brands delivering quality instrument.

 

He was promoted to vicepresident, and collaborated with scientists and personalities from that time in the construction of more complex mechanisms, being famous the Longines-Weems clock (Weems was a great US NAVY specialist in navigation), designed exclusively for astronomic navigation.

This clock was simplified later by Charles Lindberg and was turned into the more famous hour angle clock, designed to navigate with the Sun and the stars, built by Longines driven by Heinmuller.

The last version of this hour angle clock is this :

LONGINES SIDEROGRAPH

This is the version for airplane, it has an aluminium box with a electric heating to keep the watch oil sufficiently heated to maintain its accuracy, it has light for night use, and a system to take precision interval measurements.

The Siderographs is equipped with chronometer calibre 21.29, at the time the most accurate movement Longines possessed, double split-seconds recorder, anti-magnetic beryllium pallet fork, 30-hour power reserve indication and stop feature. Chronograph pushbutton at 10 o'clock, knob for setting 60 seconds revolving dial at 7 o'clock, winding/setting stem at 1 o'clock, stop lever at 12 o'clock.

HOW IT WORKS

THis clock does not measure time, it measure angles, earth turns around the sun every 24 hour that is a complete round an angle 360º every 24 hours, in the clock is shown with number 2, 360º dial indicated by the black hand, one round every 24 hours.

From the ratio 360º in 24 hours, we know 1 hour or 60 min corresponds to 15º, and therefore 1º corresponds to 4 minutes of time. Scale with number 3 we have degrees, one round is 10 º, red hand mark in this scale, for each degree takes 4 minutes, so a full round takes 40 minutes.

In scale with number 1, we have minutes of grades, each grade has 60 minutes as shown in the scale, number 5 in the picture is the long black double retrapante hands shows minutes, a full round takes 4 minutes time.

Number 4 is the indication of power reserve.

Exterior dial is used for dead reckoning navegation and helps to reslve some spherical trigonometry problems.

LONGINES WITTNAUER US TYPE A-11

This model is the 7 jeweled A-11 with 2 barrels for 8 days reserve power. Used in IIWW.

This Longines Wittnauer accomplish regulatotions to be designed as AN-5743 of the US ARMY

 

 

 

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