the number four in ancient roman clocks is usually written as IIII instead of IV

In ancient Roman clocks, as well as in many traditional European clocks, it is indeed common to see the number four represented as "IIII" rather than "IV". Although this deviates from the conventional Roman numeral system where "IV" is the correct representation for the number four, the use of "IIII" became a tradition in clockmaking.

The specific reasons for this deviation are not entirely clear, and there are several theories:

1. Aesthetic Balance: Some speculate that using "IIII" creates a more symmetrical appearance on the clock face, especially since there are twelve hours in total.

2. Design Continuity: Clock makers might have continued a tradition or design choice that they inherited from earlier craftsmen without necessarily being aware of or concerned about the Roman numeral rules.

3. Ease of Manufacturing: Another practical theory suggests that during the manufacturing process of the clock's face, it was easier to stamp or carve four identical "I" marks rather than a different character such as "V" for "IV".

4. Avoidance of Religious Symbolism: In some interpretations, the "V" shape can be associated with the Holy Trinity in Christian symbolism, and by using "IIII", clockmakers may have sought to avoid inadvertently invoking religious references on secular items like clocks.

Despite these theories, it's important to note that the use of "IIII" on clocks does not reflect an exception or variation in the standard Roman numeral system used in ancient Rome itself. Rather, it's a unique tradition that developed within the craft of clockmaking.

In most contexts outside of clock faces, "IV" is still the correct and standard way to represent the number four in Roman numerals. The use of "IIII" on clocks is a fascinating historical and cultural exception but should not be taken as evidence that "IIII" was the norm in ancient Roman times.