I have another rather obvious question. Does a mechanical (not automatic) watch tend to run slower when it’s close to the end of its power reserve? At least that’s what I’ve noticed in my 1858 Tachymeter. After I took Nico’s advice and demagnetized the watch, it seemed to run only within a few seconds fast (initially it was running close to 20 secs slow). Of course I was relieved. However, after a couple days of running properly, I noticed it running slow again compared to my iPhone. It first freaked me out but then I just let it keep running for the next few hours until it stopped on its own as the power reserve ran out. Then it just dawned on me that that might be the reason. Is my theory correct that a watch runs slower in the last few hours of its power reserve getting close to empty?