Hi Chaps - I do not understand why the majority of long case clocks have a nail protruding on the inside of the front section of the cases, just below the pendulum doors?? I have often wondered why?! Can someone tell me the idea behind this? I recall one of my clocks needing rewinding once and because the weights were of large diameter and below the level of this nail, the centre weight got scraped on this nail! Does it serve a purpose?