NavList:

"...replacing the crystal in a quartz-movement clock keeping solar mean time might be an idea [...] The mechanical route is a different story altogether, perhaps easier, if more expensive." -Christian Scheele

I was actually mulling over adjusting my mechanical stopwatch to achieve this effect. Under the back cover, there is a convenient adjustment mechanism. I have managed to get the stopwatch to run accurately to within a second over about a six hour period. Not bad in my opinion, considering the watch was only meant to time fifteen minute periods. The [former] maker of the sidereal wall clock also has a device on offer "...which measures mechanical clocks and watches with unprecedented precision. It can measure beat times to within a millionth of a second and resolve rate errors as small as one second per week." I'm sure I could use something like that to adjust my watch to run four minutes fast. However, I think the device may be out of my price range. So, I think you may be right. :)

Regards,

Sean C.