I am in the process of restoring an early Scottish longcase clock. There are no weights with the clock. Can anyone help with a 'rule of thumb' or a more technical formula for determining the appropriate weights?
I have seen weights around 12lbs, but have also seen them as much as 19lbs.
Any help would be gratefully received!

Jack, I would start with maybe 8lb for time and 10 lb for strike.

Jack, After a rather long process on mine I ended up with about 10 lbs on the time and 11.5 on the strike. It would have run with a little less on the time side but 10 made it very reliable and made me comfortable. Mine is 8 day duration. 30 hours, I assume take less. For your comfort start with a weight that is adjustable (bag of stones) subtract a little weight at a time until the clock won't perform then add enough so it does run and swings the pendulum PAST the 'tic" and "tock" evenly on both directions. Mike