Interestingly, it implies that compasses sold at different latitudes therefore should have different counterweights. Which makes sense but is not something I think would have been practically possible or commercially desirable. A compass made for Florida will be a nuisance in Scandinavia and vice versa!
Yes. I believed that the whole point of the pendular suspension of the compass card was to eliminate the need for balance weights, so that the compass could be used anywhere in the world.
It looks like anyone thinking of flying from London to Capetown will have to consider the need to change the compass half way.
MJ
