why abbreviate ? writing with quill pen was hard work - look at most documents of period pre 19th C and heavy use is made of abbreviations (eg bars over repeated letters, the ' used in possessives came from using ' as a sign of a missed letter and for possessives this was 'e' as old English like German declined nouns and 'es' was the possessive suffix) - prob the pre 19thC equivalent of texting!