There is also someone who maintains that the number IIII was maintained by superstition. It was said that the IV corresponds to the first two letters of Jupiter [IVPITER in Latin], the Roman god, and therefore its use to name a number could be considered inappropriate and blasphemous.
Other explanations point to the symmetry (the symbol is the only one that appears in the first four hours, the V appears the next four hours and the last X four, providing a symmetry that would be altered if the IV were used), comfort (IV is more difficult to read given its position on the clock face, since it is almost face down), confusion (the number IV could be confused with the VI when both are face down) or simply for economy (the clocks were manufactured in a artisanal and the numbers were made with molds, then sticking to the sphere.
A way to economize was making the molds with the set of each number, so, to make a clock, you needed to mold with four X, another with four V and five molds with four I).
Why in some watches the 4 appears written IIII and not IV? (PART I)
Why in some watches the 4 appears written IIII and not IV? (PART II)
