^ yea, dio cassius/ cassius dio kinda... said things were true if there was the slightest possibility they were true...
another source for the eruption of ad 79 is pliny the younger- he was watching it from i think either misenum or something and he had to flee. also, his uncle pliny the elder decided to go off and investigate via going on a boat towards the vulcano (hmm... slightly um... stupid?) and then he died.
i think it was a letter to someone, and it's from his description of the cloud of ash and crap, the different stages of the eruption that modern hisotirans are able to piece together what probably happened. however, there's some things that make it a bit unreliable e.g. he's writing it about 20 or 30 yrs after he experienced it, he's also trying to immortalise his uncle and make him into some great hero... so maybe exaggeration? also uses lots of sparkly language like comparing the eruption to storm gods or something running around (???)
mmm... sorry for the chunk of writing... >< yep, dio's unreliable ^^