If you work on watches you understand how welcome it is when the watch has adjustable balance weights called "mean time screws". These are special Balance screws with longer threads and usually made from a harder, heavier meterial. The longer thread is also a "jam thread" that holds its position in the screw hole without being "tightened". That way you can use them for that final "kiss" to TRY and bring the time accuracy within a second or two a day.

Sadly nearly all Elgin watches were made without the use of any mean time screws to allow "tweaking" the timing (was that a boast or a challenge?).

Saying that, even Elgin resorted to using an adjustable mean time screw on their highest end watches.

In the pictures below you can see a "normal" Elgin wheel on the right and an Elgin Father Time wheel on the left showing one of the four "mean time" weights which is a jam nut screwed onto a threaded steel stem. Quite complicated, but it DID solve the problem with jam threaded mean time screw stems breaking off in the balance wheel.