Looking at the watch above I'm wondering what the dial that goes to 42 is all about? Unless a country has 6 weeks in a month I'm at a loss. ???
The technical name is "Reserve de Marche". Basically, a fuel gauge. It measures the hours of reserve left in the main spring until the watch unwinds to a halt. Some watches will have "twin barrels". The barrel is the cylinder that holds the coiled mainspring. With two barrels, you can have either a watch that runs twice as long (some up to 100 hours without winding), or you can run a second complication, like a mechanical alarm.
