Old diacritic?

[Daniel]

So I've been reading the original 1582 Rheims New Testament and I noticed an interesting typographic feature that I'd never come across before (probably because I don't often read stuff printed back then...)

So, apparently when there's a vowel that is immediately followed by an "n" or "m", you can get rid of the "n" or "m" and put a tilde over the vowel.  e.g. "seven" can be written as "?eu?".  I was wondering if anyone knows anything about this?  Is it just done to save space or something?  It doesn't seem to be consistent throughout the text (i.e. sometimes "seven" is spelled "?eu?" but sometimes it's just "?euen").

[Ancilla Domini]

Before the modern era scribes often abbreviated common words and used various diacritics to indicate that letters had been omitted. It was common to replace nasal consonants - m or n - with a tilde over the preceding vowel.

[Ancilla Domini]

This was done to save time and effort as well as space.

[Daniel]

Interesting.  Thanks.