[drdeca]

I don’t think the “before 1830” case is really an issue. That’s just an example of the meaning of words changing.

I didn’t mean that “ordinary camera” should be a term in the formal ontology. I meant something more like “If you want to formalize the notion of ‘a camera’, it should include the CAT machine and telescope. If you want to address only the types of cameras that you think of as ordinary cameras, you should add extra qualifiers to get at what you mean.” .

(Where, “what you mean” might not get the term “ordinary camera”, but something more clear and descriptive.)