[The Squatter of Amon Rûdh]

Indeed so. It seems to me that this is what Tolkien meant when he said that Middle-earth is our world at "...at a different stage of imagination", rather than an earlier stage in its history. In an historical novel coffee would be a ridiculous and unforgivable anachronism, and one which Tolkien could have avoided easily. As it is, it exists in a deliberately anomalous society, which owes most of its more anachronistic features to the device used in The Hobbit of pitting an Edwardian country gentleman against figures of legend. I think that's one of the most overlooked themes in Tolkien: that in his first novel, modern values and approaches save situations that would become disasters if left to the mythic heroic code of conduct. This approach only works because the Shire is a place in which coffee, tomatoes and potatoes, not to mention mechanical clocks and pipe-smoking, can exist.