[In Andrews' _Latin-English Lexicon_ our correspondent will find
the following as the second definition of _AEra_, "AERA, AE, f. (from
_AEra_, the plural of _AEs_), a word belonging to Later Latin. 1. In
Mathem. _The given number, according to which a calculation is to
be made._ Vitruvius (Vetrubius) Rufus in Salmas. Exerc. I. p. 483.
2. _The item of an account_ for which in the class. _per aera_, as
plur. of _aes_, came into use. Ruf. Fest. in Breviar. _in_. The
passage of Lucil. cited by Nonius, 2, 42., _aera perversa_, is
prob. also plur. 3. _The era or epoch_ from which time is
reckoned."]
_Tudur Aled._--Can any of your Cambrian correspondents inform me when
Tudur Aled, a Welsh poet, flourished; and in what collection his works
are to be found?