Definition of "lonesomeness"

Wake up, by-and-by, and look to see what done it, and maybe see a steamboat, coughing along up stream, so far off towards the other side you couldn't tell nothing about her only whether she was stern-wheel or side-wheel; then for about an hour there wouldn't be nothing to hear nor nothing to see—just solid lonesomeness.

1884 December 10, Mark Twain [pseudonym; Samuel Langhorne Clemens], chapter XIX, in The Adventures of Huckleberry Finn: (Tom Sawyer’s Comrade) […], London: Chatto & Windus, […], pages 169–170