Clink Street, London, 7th June 2013
There is a centuries-old tradition in the way Roman numerals are written on timepieces. It relates to the fact that the dial is circular, but if the verticals ('stems') are not parallel, they look odd. Likewise if the horizontals ('rails') are not concentric with the central axis, they look odd. The result is a unique and beautiful compromise, maintaining symmetry while continuing to allow plenty of scope for individualism.
Symmetry: Write the stems first, as if you are writing in a straight line. The 'I' digits will be parallel.
Beauty: Write the rails as arcs of two concentric circles. Extend the stems in straight lines until they meet the rails.
Individuality: There is no typeface for this. Each new design is has to be hand drawn. This gives Roman numerals a slightly edgy, random feel. IIII usually looks better than IV, but there is no hard and fast rule.
It's been this way for nearly a millennium. The people who refined these rules live through us - their values are passed down from our fathers and mothers, and theirs before them. Either the look is beautiful to us because it's been around so long, or it's been around so long because it's so beautiful. Who knows which.