A Cognomial Theorem

My pursuit of the genealogical wheeze over the internet for the past few years has thrown light on a lot of family stories ("so that's what she meant by . . .") and thrown no light whatsoever elsewhere: i.e., was my great-grandfather deliberately trying to hide from his descendants or is his absence from vital records just a co-incidence?

One of the more  delightful sources has been John Grenham's column in The Irish Times.  This week's on the re-Gaelicization of Irish surnames includes this:

For example, the American pronunciation of the surnames Cahill (“KAY-hil”) and Mahony (Ma-OWN-ey) often has Irish people sniggering up their sleeves. But these pronunciations are much closer to the original Irish-language versions of the names. The fork in culture between Irish-America and Ireland preserved something over there that we over here have anglicised more thoroughly.

Aha!  So our American pronunciations are not automatically a barbaric degradation but perhaps a conservative preservation of tradition.  I have a new weapon in the pronunciation wars.  A chink has been found in the armor of She Who Must (almost always) Be Obeyed.