Ulysse Nardin GMT +/- Perpetual 38.5mm

Isn't it Christiaan's birthday today?
At least that is what the member's list says ;-)Happy Birthday Buddy!

Horology 101 - mainspring barrels
Mainsprings were originally just connected to the inner barrel wall on one end and to a center post on the other. This created a few problems. Since the barrel was rotating one way while the watch was ticking, but in the opposite direction while it was being wound, the watch lost time during winding. Also, if the mainspring broke it caused a violent snap and a surge in the opposite direction which would break other parts like jewels and gear teeth. Lastly, the watch was not isochronistic since a fully wound mainspring pushes the gears with much more force than a nearly exhausted spring. The first solution was to add a fusee between the barrel and the gears. The fusee is a conical piece that had a chain wrapped around it which wound up to the point of the cone as the mainspring was wound. A fusee from a Hamilton marine chronometer:As the watch ticks the chain unwinds gradually down the cone to the larger diameter portion. The thicker the part of the cone, the more rotational torque it g

a review.
please check this out.watchtalkforums.info/forums/s...ead.php?t=4258

can a regulation drift?
Hi - I have had my three black bays between about 5 and 8 months. The black on bracelet has been consistent at about -1.5 from the beginning. The red on leather moves around a bit....was -1.5, now hovers around zero....some days plus a second or two and sometimes minus. Although when I take the red one off the winder, it seems to gain couple of seconds in a couple of hours...this has happened twice and I guess it is just an idiosyncrasy of the watch...it then stabilises very quickly and gains nothing pretty much for the next 24 hours.The bronze which is the last one I bought was the best of the three and running at less than -1s/d for ages and recently has moved up to -2s/day and in the last 24 hours I would say has lost nearly three seconds. At what point should I send it in? I think they are meant to be COSC -4/+6 plus an extra 2s either side for Tudor - so -2/+4. I'd feel a bit stupid for sending back a watch that is running 3s slow per day! But at ¡ê3k, I would expect it to

Why no GMT ads ?
I am curious and thought I¡¯d throw this out there. Since getting my gmt nearly two years ago I have yet to see any Rolex print ads featuring a gmt. I read several newspapers on line and magazines as well and have yet to see one.What gives?