What does "stat 1. c.18" mean?
This is a legal reference. It means something like "By the twelfth year of the reign of Queen Anne, too, the first statute of the session of Parliament for that year, chapter 18."
https://en.wikipedia.org/wiki/Regnal_years_of_English_monarchs
Since Anne reigned from 1702-1714, her twelfth year was her final year.