» Fri Apr 05, 2013 12:03 pm
http://www.gamesas.com/topic/1446034-black-books/page__st__60 (Just look through that thread page; I don't want to retype all of my rants [again]).
There is an obscure reference to cannons in a http://www.uesp.net/wiki/Daggerfall:Jokes, and there are vague, unsupported, maybe-memories of cannons in Redguard (in other words, there probably aren't any cannons at all in Redguard).
And, as I and a few others discuss in the linked thread, I really don't like the idea that the Japhet's Folly fireballs are fired by cannons. I think that there was another thread in which I conceded that I would be fine with the fireballs being catapults, because that has more precedent and I personally think that it is more interesting, but I can't find the thread.
Burdened Fireballs and/or spell-scrolls-as-cannon-ammunition really seems more interesting to me...
In short, there is nothing conclusive about cannons in TES, other than one direct reference and one event that had a slim chance of involving cannons.
But it's RP, so none of that really matters all that much.