>>>>historical can actually go both ways though because the "H" in historical is unstressed. You can write "An historical" but it would be "A history." Not very clear is it? :o) My English teacher (in the 60s) would enforce "A historical" because that was the rule.
>>>>
>>>Ok, this link seems to contradict.
>>>http://www.m-w.com/dictionary/historic
>>
>>Contradict with what?
>
>The "an historic" is the right usage according to the link.
>having great and lasting importance an historic occasion

I don't contradict that. I said that's what I'd say. If you're referring to Tracy's "A history" though, she's right: "An history" sounds weird, as "an 'istory" sounds "common" in the sense of bad English of the masses (I come from a city, Liverpool, where, like London, the accent tends to drop "h"s and the "g" at the end of "Ing".
e.g. "he went swimming" -> "e' went swimmin'"

Let's say this diparity exists only with the adjectives then, as a rule of thumb.