The most recent (1997) novel written by Thomas Pynchon. In it, the Rev'd Wicks Cherrycoke tells the story of the famous astronomer and surveyor to his family, during the Christmas of 1786. Cherrycoke is a liar, so we don't know how much of his story is invented to entertain his nieces and nephews.

The book is written in the voice of an 18th century storyteller, and although its outline is historically true, the real action is in the bizarre episodes that occur throughout the novel. Pynchon's genius lies in his ability to craft passages of incredible beauty and strength, right alongside the slapstick comedy and disjointedness of the main plot.

A recurring theme in the novel is the conflict between the scientific, materialistic view of the universe, being advanced by Mason and Dixon, and the older world of the spirit that this outlook was replacing. This is an old theme, and its hard to think of much new that can be said about it. In roughly the same historical time as the novel's setting, the poet William Blake was writing of the insignificance of Newton's physics next to the world of the mystic:
The atoms of Democritus
And Newton's particles of light
Are sands upon the Red Sea shore,
Where Israel's tents do shine bright.
Pynchon takes up on this theme, and gives it new relevance, in this passage from chapter 34, thought by the melancholy Mason as he camps on the edge of the Western frontier at Lancaster, Pennsylvania:
Does Britannia, when she sleeps, dream? Is America her dream? - in which all that cannot pass in the metropolitan Wakefulness is allow'd Expression away in the restless Slumber of these Provinces, and on West-ward, wherever 'tis not yet mapp'd, nor written down, nor ever, by the Majority of Mankind, seen, - serving as a very Rubbish-Tip for subjunctive Hopes, for all that may yet be true, - Earthly Paradise, Fountain of Youth, Realms of Prester John, Christ's Kingdom, ever behind the sunset, safe till the next Territory to the West be seen and recorded, measur'd and tied in, back into the Net-Work of Points already known, that slowly triangulates its Way into the Continent, changing all from subjunctive to declarative, reducing Possibilities to Simplicities that serve the ends of Governments, - winning away from the realm of the Sacred, its Borderlands one by one, and assuming them unto the bare mortal World that is our home, and our Despair.
These fine asides, pretty much able to stand on their own as tiny essays, make this novel a worthwhile read.