unicode symbol(s) for a long syllable in a Latin text

Question

I want to write the following line (Ovid, Metamorphoses, X.30) with its metric peculiarity :

per Chaos hoc ingēns uāstīque silentia rēgnī

(something like : By this huge void and these vast and silent realms...)

It's a dactylic hexameter with the "hoc" being treated as a long syllable (for another example, confer this line in Eneid 2.664 : Hoc erat, alma parens...)

 -    u u  -  -  -    -  -  u  u -  uu  -  -
per Chaos hoc ingēns uāstīque silentia rēgnī

My question is : how can I show that "hoc" is treated as a long syllable ? I don't want to use a macron ("hōc") since the vowel is short (hoc < hodce; the word being read "hocc"). I can't use some wordprocessor or CSS tricks : I have to use pure Unicode output. I thought to the synizesis symbol (something like ho͡c) but this Latin word had nothing to do with a synizesis !

Any better idea ?

Answer 1

I do not see any problem with the way you did it in your second grey box: you put a macron immediately above the long vowels, and indicated the scansion of the verse (heavy and light syllables) in a separate line above the text. That is standard procedure. But if you want to call attention to the unorthographic scansion of “hoc”, you could always write “hoc(c)”, that is: “written hoc but presumably pronounced hocc”.

Answer 2

Some American textbooks for (modern) languages will use an underdot (U+0323) to represent stressed syllables that must be memorized.

As long as you explain to your reader what you mean, that could be a good alternative:

per Chaos học ịngēns uāstīque silentia rēgnī

Doesn't look as good with SE's default font, but most serif fonts I've seen prints quite nicely. If it's for screen use, instead of the dot, you could maybe go for U+0329 (vertical line underneath) for better visibility: “per Chaos ho̩c i̩ngēns…”