A chara, – Micheál Ó Ruairc (August 24th) is correct when he says that Dinneen has “blá” as masculine. Royal Irish Academy Contributions, however, gives it as feminine. While the latter concerns itself mainly with earlier forms of the language, many Irish place names also retain features which have not survived in modern Irish.
A good example of this is An Muileann gCearr, which owes its eclipse to its neuter noun, no longer a feature of the language.
This is, as Mr Ó Ruairc says, a case of “if it’s not broke don’t fix it”.
There was a tendency to assume that forms that did not appear to conform to modern rules were incorrect and so an eclipse was removed from the Midlands and transposed to West Cork in order to satisfy the “purists”! – Yours, etc,