Interesting read. This caught my attention:
> Middle Earth is framed, explicitly, as an account of the history of our world. That is, the world of the Lord of the Rings is one and the same as our world, just at a very different point in its history. Thus, while Middle Earth may possess resources that we do not, such as Mithril, unless the resources of our world were deposited later, they must have been available to the people of Middle Earth.
I think this is a common mistake when analyzing Tolkien's work. His universe isn't meant to be the history of Earth, it's supposed to be an origin myth of England. With all the caveats that go with similar origin myths. To quote the letter that prefaces The Silmarillion:
> I was from early days grieved by the poverty of my own beloved country: it had no stories of its own (bound up with its tongue and soil), not of the quality that I sought, and found (as an ingredient) in legends of other lands.
Why hasn't the world of LoTR had an industrial revolution? Well for the same reason Troy didn't. Because if it did, it wouldn't be an origin myth. It's no more reasonable to discount the worldbuilding of Tolkien for incongruences with history than it is to discount the "worldbuilding" of Homer.