this is my New Haven mirror clock that is slowing down so that it is losing 8 or 9 minutes after 3 or 4 hours after winding. The setting on the back is already all the way over as far as it can go to fast. My question is how do these clocks work? will they slow down as you get closer to the 24 hr that it winds to? and what is that little hole for,that is below the curved opening? My wife says it's just slowing down because, like the 2 of us, it's getting older and doesn't work as well. Can I try some light oil down that hole? I want it to work better. terry