Less than 2 hours before lots begin closing in our Fine Watches online sale at 10 AM ET, including this Pink Gold Lange 31. A true technical tour de force, this was the world’s first mechanical wristwatch with a power reserve of 31 days and a patented constant-force escapement that continuously delivers uniform torque from the first to the last day of use. But how does it work? To achieve such power, the hand-wound caliber L034.1 featuring 62 jewels contains two mainsprings, one housed on top of the other, both 1850 millimeters (roughly ten times what is found in watches with conventional power reserves). Rather than winding these mainsprings via the crown, you would use a ratcheting winding key that connects to a port in the case back to manually wind the barrels. To ensure the smooth application of this astonishing power, a patented ‘constant force’ escapement with remontoire spring ensures the uniform levels of torque are delivered. There's still time to bid on this and more in o...