Hi All, After a couple of expensive purchases, I need to balance the books a little. Up for sale is this really interesting piece of horological history. I've got it up on the bay, so will copy my sales pitch from there:- The Favre Leuba Bivouac was the first mechanical wristwatch that could measure altitude and air pressure. This is a reference 53203 from the late 1960's with a silver dial, black bakelite bezel and the original vintage stainless steel bracelet. All in superb condition and case measures 40mm ex crown. Founded in the 18th century, Favre Leuba is one of the oldest watch companies in the world. The motto of the brand is "for those who conquer frontiers". The Bivouac is a barometer, altimeter and a timepiece at the same time. The silver inner bezel shows the air pressure in mmHg (millimeters of mercury). The black bezel shows the height above sea level up to 10,000 metres. If the rotating bezel is in the starting position, the height above the sea (outer bezel) and the average air pressure at this height (inner bezel) are in line. If you know the current above sea level, you can read the average air pressure. If the red hand points to a lower value, the air pressure goes down, so the weather is getting worse, but if it points to a higher level, it will be sunny. This watch was really revolutionary at the time and really pushed the boundaries of mechanical watch making. The air pressure element works by use of an aneroid barometer with the role of altimeter and barometer. Aneroid means "using no liquid" and places a vacuumed metal container on the movement, and the expansion and contraction of this container is used to show the air pressure. Watch is running well and has obviously been very well cared for throughout it's life. I haven't tested the altimeter or barometer though as I haven't had the time to work it out! I took the 1st and 2nd pictures about a week after the rest, so it's obviously working. There are a couple of youtube videos though:- Looking for £2,450 by. Includes insured postage within the EU. Happy to discuss options outside of the EU. Payment by BT please. Any questions, please ask I have a few bits of feedback here but the majority is under the same username at TZ-UK. Cheers, Steve **SOLD ELSEWHERE**